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An assessment of the potential of green roofs for bird conservation in the UK

Helen Burgess

May 2004

An assessment of the potential of green

roofs for bird conservation in the UK

Helen Burgess

May 2004


ABSTRACT

This project aimed to determine the benefits that green roofs currently provide for birds

and assess their potential for aiding conservation efforts in the future. Two roofs were studied in

East and West Sussex between January and April 2004. It was found that 70% of the total

duration of all activities involved the use of resources provided by the vegetation, i.e. birds spent

most of their time feeding and collecting nest material. Four species of high conservation

concern and two species of moderate conservation concern were observed using the roofs.

The study concludes that if careful consideration is taken over the design of green roofs, then

they could play an important role in helping secure the future of some of our most threatened

birds.


ACKNOWLEDGEMENTS

I would like to thank Dusty Gedge for his time, guidance and invaluable support throughout

the project. My thanks also go to Stephan Brenneisen for taking the time to show me the green

roofs in Basel and for his help at the start of the project. I would like to thank Gyongyver Kadas

for her advice and encouragement.

I am grateful to those who helped gain permission to work at the Rolls-Royce site;

Stephanie Sherlock, Howard Mosher and Nigel Carter. I am also grateful to the residents of

The Diggers for allowing me to use their communal garden to carry out bird observations,

especially Rosie Bradshaw.

My thanks also go to Catherine Senger for her help in translating a section of Stephan

Brenneisen’s report and to Mathew Frith for providing me with helpful information at the start of

the project.


CONTENTS Abstract

Acknowledgements

1 Introduction 1-2 1.1 Defining a green roof 2 2 Aims and objectives 3 3 Bird conservation in the UK 4-9 3.1 Population status of UK birds 4

3.2 Threats to birds and the role green roofs can play in reducing them 5-8

3.3 Conserving the black redstart 8-9

4 Background to green roofs 10-17 4.1 History 10

4.2 Types of roof 10-11

4.3 Benefits 11-13

4.4 Differences in UK and continental use 13-14

4.4.1 Trip to Canary Wharf, London 14-16

4.4.2 Trip to Basel, Switzerland 16-17

5 Review of previous studies 18-19 5.1 Research in Switzerland 18-19

5.2 Relevance of study 19

6 Site selection 20-28 6.1 Site 1 – Rolls Royce factory 21-24

6.2 Site 2 – The Diggers 25-28

7 Methods 29-31 8 Limitations 32 9 Results 33-43 8.1 Summary 33

8.2 Rolls-Royce 34-38

8.3 The Diggers 39-43


10 Discussion 44-51 10.1 Rolls-Royce 44-47

10.2 The Diggers 48-49

11 Conclusion 52 12 References 53-57 13 Appendix 58-94 13.1 Typed log of observations – Rolls-Royce 59-62

13.2 Typed log of observations – The Diggers 63-67

13.3 Original log of observations 68-80

13.4 Outline of study sent to Rolls-Royce 81

13.5 E-mail from Mathew Frith (Peabody Trust) 82-85

13.6 Letter to Diggers residents 86

List of figures 1 Components of a typical green roof 2

2 Graph showing farmland bird population trends 6

3 Black redstart 8

4 The Laban Dance Centre, Deptford 9

5 Traditional sod roof house, Iceland 10

6 Chicago City Hall roof garden 10

7 Waitrose roof, Canary Wharf, London 11

8 FC4 building, Canary Wharf, London 14

9 Heat damage on FC4 14

10 View of Retail 1 from FC4 15

11 View of Retail 2 from FC4 15

12 Cross-section of roof on Waitrose 15

13 Rhypark roof, Basel 16

14 Shrub on Rhypark roof, Basel 16

15 Rossetti-Bau, viewed from roof of hospital 17

16 Water-logging on Rossetti-Bau 17

17 Location map of study sites 20

18 Ordnance Survey map showing location of Rolls-Royce factory 21

19 Plan of the Rolls-Royce factory 22

20 Rolls-Royce factory from the east 23

21 Roof of Rolls-Royce factory 23


22 Aerial photograph showing location of Rolls-Royce factory (distant) 24

23 Aerial photograph showing location of Rolls-Royce factory (close-up) 24

24 Ordnance Survey map showing location of The Diggers 25

25 The Diggers from the south 26

26 View of houses 5 and 6 of The Diggers from the north 27

27 Houses 5 and 6 of The Diggers 27

28 Aerial photograph showing location of The Diggers (distant) 28

29 Aerial photograph showing location of The Diggers (close-up) 28

30 Viewing position at the Rolls-Royce factory 30

31 View from position on embankment 30

32 Viewing position from the southeast 30

33 Viewing position at The Diggers 31

34 View from position in communal garden 31

35 Viewing position from the north 31

36 Table showing number of visits each species made to Rolls-Royce 34

37 Table showing time spent in specific activities at Rolls-Royce 34

38 Pie chart showing species visiting Rolls-Royce factory 35

39 Pie chart showing activity duration at Rolls-Royce factory 36

40 Pie chart showing type of activity at Rolls-Royce factory 37

41 Table showing number of visits each species made to The Diggers 39

42 Table showing time spent in specific activities at The Diggers 40

43 Pie chart showing species visiting The Diggers 41

44 Pie chart showing activity duration at The Diggers 42

45 Pie chart showing type of activity at The Diggers 43

46 Vegetated shingle at Dungeness, Kent 44

47 Song thrush 45

48 Ringed plover 45

49 Ringed plover on roof of Rolls-Royce factory 45

50 Pair of linnets on roof of Rolls-Royce factory 46

51 Linnet 46

52 Common gull 47

53 House sparrow 48

54 Starling and wood pigeon on roof of The Diggers 49

55 Starling 49

56 Summary table of bird species that could benefit from green roofs 51

(Cover photograph taken at The Diggers, 18th April 2004)


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1 INTRODUCTION

The populations of many UK birds have suffered rapid declines in recent years, through

the loss of habitat, agricultural intensification and predation. 65% of our species are of

conservation concern and appear on the UK or Local Biodiversity Action Plans (BAPs). Green

roofs (those that are intentionally vegetated), can aid conservation efforts for these species by

providing undisturbed areas free of agricultural chemicals which, if designed appropriately, can

also imitate habitats that are of importance in the birds’ life cycle.

Green roofs are commonplace in continental Europe, especially in Germany and

Switzerland, where the benefits of vegetating buildings have been long recognised. Along with

reducing stormwater runoff and providing insulative benefits, green roofs can act as mitigation of

habitat loss caused by development on both brownfield and greenfield sites.

There is a general lack of awareness amongst architects and developers in the UK, along

with a lack of public demand. A desktop study commissioned by English Nature published in

2003 (20) concluded that “…green roofs can provide many general environmental and

associated aesthetic and health benefits. Although individual green roofs offer local

environmental benefits, any significant contribution to wider environmental quality is only likely

to become apparent once a more substantial area of town and city roof space has been

greened. Such a programme will require political commitment and concerted action

underpinned by science, technical expertise and good design. In order to refine the design of

green roofs for biodiversity conservation, some further research and experimentation is required.”

This project studies the way birds use green roofs and examines the potential benefits for

bird conservation that could arise from more widespread use of vegetated roofs. After

consultation with Dusty Gedge (introduced in Section 4.4.1), birds were chosen as the focus of

this study as no research had been carried out on this subject in the UK and identification is

relatively straightforward.


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1.1 Defining a green roof

Also known as a nature, living or eco roof, a green roof is defined as “…an area of usually

ornamental planting whose substrate is isolated from the natural ground by a man made

structure of at least one storey” (Brownlie 1990, citied in 17). English Nature have extended the

definition to “…roofs that have been initially planted and/or sown, as well as those that have

been allowed to colonise and develop naturally” (20).

Although roofs vary in their

design, they contain many of the same

basic components. As shown in Figure

1, these components are, from the roof

upwards:

• A roofing membrane acts as the critical waterproof layer.

• A root-resistant compound prevents damage from plant roots.

• An insulation layer.

• A drainage layer draws excess moisture away from the membrane.

• A filter layer prevents soil particles from clogging up the drainage system while allowing water to nourish the plant life.

• A growing medium, usually soil.

• A surface layer of vegetation (39).

Further definition and information about green roofs is given in Section 4.

Figure 1 Components of a typical green roof (47)


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2 AIMS AND OBJECTIVES

The aim of this study is to establish whether green roofs are of benefit to birds and to

assess the potential they have for bird conservation in the UK.

The objectives are:

1) Bird species Determine which species are using green roofs and whether they are of conservation

concern.

2) Activity Determine the reasons why birds are using green roofs.

3) Conservation potential Use the findings to assess the benefits green roofs currently provide birds and the extent

to which these could be improved.


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3 BIRD CONSERVATION IN THE UK

3.1 Population status of UK birds

The population status of birds in the UK was recently assessed by 14 of the leading

governmental and non-governmental conservation organisations. Led by the RSPB, a

collaborative report was produced in 2002 which reviewed the status of 247 bird species

regularly found here (40). Seven criteria were used (global conservation status, recent decline,

historical decline, European conservation status, rare breeders, localised species and

international importance) to place each species into one of three categories: red, amber or

green.

Red list species are those:

- That are globally threatened

- Whose population or range has declined rapidly in recent years (i.e. more than 50% in 25

years)

- That have declined historically and have not shown any recovery.

Amber list species are those:

- Whose population or range has declined moderately in recent years (by more than 25% but

less than 50% in 25 years)

- Whose population has declined historically but recovered recently

- Who are rare breeders (fewer than 300 pairs)

- With internationally important populations in the UK

- With unfavourable conservation status in Europe

- With localised populations.

Green list species are those that do not fulfill any of the criteria.

Of the 247 species, 40 (16%) were red-listed, 121 (49%) were amber-listed and 86 (35%)

were green-listed. Since the last review (‘Birds of Conservation Concern’, published by the

JNCC in 1996), the total number on the red list has increased by four, with nine species new to

the list. Three species, the corncrake, aquatic warbler and Scottish crossbill are also listed on

the IUCN 2003 Red List (24). The total number on the amber list has increased by eleven. Five

species have moved from the red to the amber list because their populations have more than

doubled in the last 25 years.

The new findings, combined with additional information, are helping to guide conservation

action between 2002 and 2007. The JNCC has used this review as one element of the ongoing

Species Status Assessment Programme which has in turn informed the revision of the UK

Biodiversity Action Plan (UK BAP) which 26 bird species are currently part of (27).


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3.2 Threats to birds and the role green roofs can play in reducing them

• Agricultural intensification

It has long been acknowledged that intensive farming practices are having severe impacts

on farmland birds. According to the RSPB (41), farmland bird populations have decreased by

around 40% since 1970, with some species suffering even greater declines. Between 1970 and

1999, tree sparrows have declined by 95%, corn buntings by 88%, grey partridges by 86%,

skylarks by 52% and yellowhammers by 53%. In the past 40 years, farming has become more

industrialised with the establishment of the Common Agricultural Policy (CAP) in 1957.

The CAP encouraged increased food production and the modernisation of farms through

financial incentives which caused serious reductions in bird populations. These changes

include: contamination of food supply through input of pesticides, reduction of suitable nesting

sites through changes in sowing regimes, loss of hedgerow, effects on winter food through

reduction in over-winter stubbles, mortality caused directly by farming operations and reductions

in ley grass (9). Bird population declines have been far greater in countries subject to the CAP than in

former Communist countries, shown in Figure 2. The UK is among the countries with the

highest use of intensive practices in Europe and correspondingly has experienced the greatest

decline in farmland birds.

It is feared that the problem will worsen when a further 10 countries join the EU in May

2004. These countries must learn from the rest of Europe’s mistakes and protect their farmland

birds or the declines will continue and we may even see some species become extinct. The

red-backed shrike has become effectively extinct as a breeding bird in the UK, but in Poland

there are 30,000 breeding pairs. The situation is mirrored with other species that have declined

since the intensification of agriculture began. There are currently just 620 corncrake males in

the UK after a population decline between 1988 and 1993 of 3.5% per year, yet there are

25,000 individuals in Latvia (32).

One positive advance made recently is a new Environmental Stewardship scheme

announced by the Department for Environment, Food and Rural Affairs (DEFRA) in April 2004.

The scheme will pay UK farmers for helping wildlife on their land, which will be of huge benefit

to birds. Farmers will be encouraged to adopt working practices which best help birds to survive

on their land, including providing winter food and safe places to nest through set-aside schemes

(41).


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Green roofs can offer farmland birds a place to feed where the plants are not

contaminated with agricultural chemicals. They can be more abundant in insects that are

reduced in number on farmland where pesticide is used. They can also provide ground-nesting

birds with a safe place to breed, away from human interference.

• Habitat destruction/deterioration

Over the past 50 years, terrestrial habitats have been significantly reduced in extent and

quality due to urban development, afforestation, atmospheric pollution and, as previously

mentioned, agricultural intensification. The 40 species of bird that appear on the red list are

from a range of habitats that are facing these pressures, a few of which are mentioned below.

Vegetated shingle has become a nationally rare habitat. Figures for the loss of this

habitat are only available for Dungeness in Kent, which holds the largest proportion of the UK’s

Figure 2 The relationship between agricultural intensity and mean farmland bird population trends (57).


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shingle and has been well-studied over the years. Here, over 40% of the shingle surface has

been lost through activities such as onshore and offshore aggregate extraction and the

construction of sea defences. This is affecting the abundance of specialist ground-nesting

birds, such as little terns, common terns, ringed plovers and oystercatchers. Mixed plant

communities are capable of establishing themselves on shingle with mature grassland, lowland

heath, scrub, moss and lichens supporting a wide variety of invertebrate species which the birds

feed upon (14). Lowland heathland has also suffered a dramatic decline in its coverage. Since 1940,

England has lost over half of its lowland heathland through encroachment by trees and scrub,

fire damage, land reclamation and nutrient enrichment (15). Heathland is important for six birds

of conservation concern: the nightjar, stone-curlew, woodlark, and linnet (all red list species)

and the Dartford warbler and stonechat (amber list species).

Calcareous grassland supports a diverse range of plants and animals, with up to 40

species of plant found in one square metre. This grassland provides a feeding or breeding

habitat for a number of red list bird species, including the corn bunting and stone-curlew.

Mosaics of scrub within the grassland provide nesting sites for linnets, yellowhammers,

whitethroats and lesser whitethroats. This habitat is suffering a sharp decline in extent, largely

due to increased inputs of fertilisers from surrounding farmland which reduces the floral diversity

and lack of appropriate management such as grazing (25).

It is not just greenfield sites which are suffering a decline in bird numbers. Brownfield

sites (land which has been previously used) found within towns and cities support a variety of

species from a range of habitats which are not normally found living together (8). Species once

common in the countryside that have been affected by the increased use of chemicals in

agriculture now find refuge in city centres and many of these are nationally important (38). These sites are important for foraging and nesting birds, including the black redstart, house

sparrow, skylark, song thrush, linnet (all red-listed) goldfinch and kestrel (amber listed) (10). The ecological value of brownfield land is often overlooked by developers due to

misconceptions over which land is valuable for wildlife. The number of houses in England is

expected to grow from 20.2 million in 1996 to 24.0 million in 2021, an increase of 19% (12). The

government’s Urban Task Force, set up in 1988, recommends that 60% of new homes should

be built on brownfield sites (8). Facing such pressure, brownfield sites have become one of the

most threatened habitats.

Green roofs can be designed to imitate these habitats and provide an artificial alternative

to a birds normal feeding or breeding ground. This has already been achieved for the black

redstart in both London and Basel, Switzerland (see Section 3.3).


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• Predation

Predation of birds is a natural occurrence. Foxes, stoats, rats and hedgehogs are all

predators of ground-nesting birds. Skylarks, stone curlews, corn buntings, meadow pipits as

well as many waders such as dunlins, ringed plovers, lapwings and oystercatchers are all

affected by predation from these mammals. Urban, farmland and coastal birds are subject to

predation by other bird species. Crows, magpies and gulls raid nests to steal eggs and chicks.

Birds of prey, such as the recently-reintroduced sparrowhawk, attack from the air.

An unnatural predator however is posing a great threat to garden birds, such as starlings,

house sparrows and robins. A survey carried out by The Mammal Society in 1997 found that

domestic cats are having a substantial effect on wildlife. A total of 14,370 prey items were

caught and brought home by 986 cats from 618 households in the 5 month survey, with 24% of

prey items being birds. Extrapolation from these figures suggests that Britain’s 9 million cats

catch 275 million prey items a year, of which 55 million are birds. The most frequently caught

birds are house sparrows, blue tits, blackbirds and starlings (45). With the number of cats kept

as pets increasing, this is a cause for concern with regard to populations of garden birds.

Green roofs can provide birds with comparative safety from mammalian predators when

nesting, feeding or resting. Aerial predation however cannot be avoided and may be a higher

risk on unprotected roof areas.

3.3 Conserving the black redstart

Conservation action using roof space has already

begun to help conserve the black redstart (Phoenicurus

ochruros) (Fig. 3), one of the UK’s rarest birds with less

than 100 breeding pairs left (19). Its preferred habitat is

brownfield land and so the population is mostly confined to

urban environments. Unfortunately, the gentrification of

our city centres means its nesting opportunities are being

rapidly reduced. The bird has been adopted as a flagship

species for bringing urban conservation to the attention of

city planners.

In the late 1990’s, Deptford Creek in southeast

London was granted a regeneration fund to renew a

Figure 3 Black redstart Taken by Craig Churchill (19).


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derelict part of the city. Two pairs of black redstarts were known to be breeding on two prime

development sites. As the bird is fully protected under Schedule 1 of the Wildlife and

Countryside Act 1981 during the breeding season, this meant developers had to take measures

to secure its protection. As a result of the work of the London Biodiversity Partnership, green

roofs are now a recommended mitigation measure.

The type of green roof that is of benefit to the black redstart is of a particular kind. It has

to replicate as closely as possible the original habitat prior to development and the term ‘brown

roof’ was created. The first brown roof to be created was on the Laban Dance Centre in

Deptford (Fig. 4). It uses a mix of local crushed brick and concrete to form the substrate base

and has been left to colonise naturally.

This is one of the first developments that recognised the importance of brownfield sites

as a unique habitat that is worthy of conservation (23). It also helped raise the profile of green

roofs as effective mitigation tools for the loss of urban land that is important for a variety of

wildlife. Further roofs designed for the black redstart are yet to be built, but when complete the

Deptford area will have the largest concentration of green roofs in the UK (18).

Figure 4 The Laban Dance Centre, Deptford, as it looks today and how it is hoped to look after colonisation (30).


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4 BACKGROUND TO GREEN ROOFS

4.1 History

Green roofs are by no means

a new concept. They are indigenous

to many countries, mainly because

of their insulative benefits. Sod

roofs and walls have been used in

Iceland for hundreds of years, with

many of the examples of this region

being over 400 years old (Fig. 5).

This acted as an efficient insulator

from the cold climate and soon

became popular throughout

Scandinavia and Canada. In

contrast, grass roofs have been

used in warmer climates such as Tanzania to keep buildings cool (39). Modern examples of

green roofs in Britain are the hangers of some military airfields from the 1930’s which were

camouflaged with turf (16). In the early 1960’s, green roof technology was developed further,

mainly in Germany and Switzerland. The 1970’s saw a large amount of technical research on

the various components of green roofs (36). The green roof market then expanded rapidly in

Germany through the 1980’s, with an annual growth rate of 15-20% (37).

4.2 Types of green roof

Green roofs can be defined as

‘intensive’ or ‘extensive’, based on their use,

method of construction and maintenance

requirements.

Intensive green roofs are the often

referred to as ‘roof gardens’. They have deep

soil profiles (between 20 and 60cm) which

allow a diverse range of plants to grow,

including trees and shrubs (37). They are

Figure 6 Chicago City Hall roof garden (56)

Figure 5 Traditional sod roof house, Haukadalur, Iceland (60)


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often designed for human use and require regular maintenance to water, weed and fertilise the

vegetation. Examples include the city hall in Chicago (Fig. 6), Cannon Street station in London

and Marks & Spencers in Kensington High Street, London. A third category of green roof is

sometimes used to distinguish ‘intensive’ from ‘simple intensive’ roofs, which are vegetated with

lawns or ground covering plants are less elaborate than the first category (20).

Extensive green roofs have

shallower soil profiles (between 5 and

15cm) which can consist of a mixture of

sand, gravel, peat and crushed brick (37). The vegetation is self-sustaining and

mainly consists of succulents, mosses,

grasses or herbs that are hardy enough to

withstand the extreme micro-climate (11). They are not usually designed for human

access except for maintenance, which is

needed for the first year or so while the

plants establish. After this time,

maintenance is minimal, with visits

needed for the removal of invasive species and membrane inspections. Examples include the

Waitrose roof in Canary Wharf, London (Fig. 7) and Paignton Zoo, Devon.

Factors such as the structural capacity of the building, budget, plant availability and

building needs mean that these definitions may not be clear cut and some roofs may be a

combination of both intensive and extensive systems. 4.3 Benefits

Green roofs provide a wide range of social, economic and environmental benefits for both

the building owner and the general public:

Storm water retention Precipitation in cities is prevented from percolating the ground by impervious surfaces

such as concrete and tarmac and 75% of rainwater can become run-off (43). The vegetation

and growing medium of green roofs act as sponges and retain rainwater, which has potential

Figure 7 Waitrose roof, Canary Wharf, London (Taken 6th August 2003)


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benefits for urban planning with regard to flooding. Extensive green roofs can retain up to 75%

of rainwater in the short term and between 15-20% can be held for up to 2 months (20).

Energy conservation A vegetated roof acts as an insulation layer and buildings are made cooler in summer and

warmer in winter, reducing energy consumption and cost. Research undertaken at Nottingham

Trent University has shown the following results:

• With a mean daily temperature of 18.4°C, the temperature beneath the membrane of a

conventional roof is 32°C whereas the temperature beneath the membrane of a green roof

is 17.1°C.

• With a mean daily temperature of 0°C, the temperature beneath the membrane of a

conventional roof is 0.2°C, whereas beneath the membrane of a green roof the

temperature is 4.7°C (30).

Reduction of urban heat island effect The urban climate is usually warmer than that of the surrounding countryside, a

phenomenon known as the ‘urban heat island effect’. Vegetation effectively absorbs heat to be

later released in evapotranspiration and so green roofs can play an important role in reducing

urban temperatures.

Improvement of air quality The urban heat island effect is also the main cause of ozone production in cities which

contributes to the formation of photochemical smog on particularly warm days. Vegetation is

able to filter particulates and absorb gaseous pollutants through photosynthesis and so green

roofs can reduce atmospheric pollution (37). One study reveals that a 2,000m2 of unmowed

grass on a roof could extract 4,000kg of dirt out of the air (36).

Noise reduction The soil of a green roof blocks lower sound frequencies while the vegetation blocks the

higher frequencies (37). Together these elements form an effective sound barrier and reduce

noise by 8 dB or more (21). This makes them ideal for use on buildings near noise sources

such as airports, motorways and in industrial areas.

Extended life of roof A layer of vegetation can protect a roof’s surface from UV radiation, climatic extremes and

mechanical damage and so improve its longevity. One estimate suggests a green roof can

outlive a tiled roof by three times as long (43).


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Reduced costs As a result of the extended life span of a green roof, fewer replacements and maintenance

work is needed, thereby reducing future maintenance costs. Although initial costs can range

from between three and six times the cost of conventional roof systems, green roofs may be

less expensive and outperform traditional roofs in the long term (46).

Aesthetic improvement

The additional vegetation provided by green roofs helps to visually soften the built

environment and can aid the mental health of those living and working in cities (10). The variety

of smells, colours and movements provided by plants can significantly add to people’s well

being (36). Urban hospitals have been designed with this in mind to help aid the recovery of

patients as they seem to respond well to having green areas within sight (35).

However, the two benefits of relevance to this study are:

Provision of additional habitat Vegetating a roof makes a previously unused surface available for use by people or

wildlife. Open areas are often restricted in urban centres, but a greened roof provides an

alternative open space for recreational purposes and offers a contrasting type of habitat to the

artificial, grey landscape of cities.

Improvement of biodiversity Vegetated roofs are of far greater benefit to wildlife than conventional roofs.

Developments on greenfield and brownfield sites cause the loss of habitats and their associated

wildlife. Green roofs can act as mitigation for this loss and can even be designed to meet the

specific requirements of certain endangered species.

4.4 Differences in UK and continental use

The benefits of green roofs are numerous and varied, yet compared with continental

Europe, the UK has very few examples. Our traditional and conservative approach to building

development has meant the unfamiliar concept of green roofs has not yet become established.

Developers are deterred by what they perceive to be extra costs or complications. Technical

problems can be overcome but guidance is not readily available at present.

Several European cities incorporate green roofs into building regulations. Vienna offers

grants and subsidies for developers who use green roofs in new constructions and Stuttgart


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requires all new flat-roofed industrial buildings to have vegetated roofs (37). In Switzerland,

laws require that 25% of all new commercial developments include green roofs and 43% of

German cities offer incentives for their installation (20). Improvements in air and water quality,

as well as reductions in storm water runoff, have been the key benefits that have motivated the

development of the green roof industry in these countries.

To compare the differences first-hand and develop my background knowledge, I visited

green roofs in London and Basel, Switzerland during the summer of 2003.

4.4.1 Trip to Canary Wharf, London

On 6th August 2003 I met Dusty Gedge, an ornithologist who is the consultant ecologist

and co-coordinator of the London Biodiversity Partnership’s Black Redstart Action Plan and a

leading figure in green roof circles in the UK. Dusty advises a number of governmental and

non-governmental bodies, architects and the green roof industry and was to become my mentor

for this project. I also met PhD student Gyongyver Kadas who is studying green roofs with the

London Biodiversity Partnership and the Royal Holloway University of London. The buildings of

Canary Wharf feature 30,000m2 of green roofs which have been installed since 2001, some of

which occur at heights of over 70 metres.

Figure 8 FC4 building, Canary Wharf, London (Taken 6th August 2003)

Figure 9 Heat damage on FC4 (Taken 6th August 2003)


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Most green roofs in the UK are made from sedum matting. This is the preferred material

of developers as a vegetated roof can be instantly achieved which involves little or no

maintenance. But as I was able to see on the FC4 building, sedum matting suffers in the

extreme heat when the mats peel and the plants turn red in colour (Fig. 8 and 9). This roof was

laid 5 years ago, is 800m2 in size and uses a shallow substrate which is just 2.5cm deep. The

sedum is managed intensively, with weeding taking place every third week, fertiliser added once

a year and any bare ground replaced with sedum.

From FC4 it is possible to see the roofs of Retail 1 and Retail 2 (Fig. 10 and 11). These

roofs are surrounded by tall buildings and receive little sunshine. As a result, they are relatively

damp and the sedum is much greener.

Ms Kadas’ report of invertebrate diversity

on green roofs (28) found that roofs with deeper

substrate supported the highest number of

species, as well as those which included

structural and vegetative variation. This is seen

on the Waitrose roof in Canary Wharf (Fig. 7)

where 7cm of crushed brick is used under the

sedum matting (Fig. 12) and areas where no

vegetation grows provides ideal conditions for

invertebrates.

Figure 10 View of Retail 1 from FC4 (Taken 6th August 2003)

Figure 11 View of Retail 2 from FC4 (Taken 6th August 2003)

Figure 12 Cross-section of roof on Waitrose (Taken 6th August 2003)

7cm


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At the time of writing, Royal Holloway University of London and the London Biodiversity

Partnership project were about to install a green roof laboratory located on the HQ4 building.

The purpose is to test different substrate and planting regimes in order to establish the

important design factors needed to provide mitigation for brownfield invertebrates on green

roofs.

4.4.2 Trip to Basel, Switzerland

I spent a week in Switzerland in September where I spent one day with Stephan

Brenneisen of the University of Applied Science, Wadensvil. Brenneisen made a four-year

study of green roofs in Basel and Lucerne and until 2002, this was the only published work on

the biodiversity of green roofs. Numerous endangered species of beetles and spiders were

recorded and of particular interest to this project, so were broods of endangered birds (see

Section 5.1 for details).

On 8th September, I was shown ten roofs in Basel that were used in the study. In contrast

to the UK where there are only a few examples of aggregate-based roofs, every roof I was

shown in the city incorporated varying depths of aggregate.

The roof at Rhypark (Fig. 13) was constructed 14 years ago and is the oldest in the study.

It is made from a chalk rubble substrate that varies in depth from 8cm to 50cm where shrubs are

able to grow (Fig. 14). This roof is used by house sparrows which nest in the window blinds of

the adjacent flats and feed on the seeds of the roof plants.

Figure 13 Rhypark roof, Basel (Taken 8th September 2003)

Figure 14 Shrub on Rhypark roof, Basel (Taken 8th September 2003)


17

The added weight of substrate, vegetation and collected water is accounted for in the

design of the buildings. I was visiting at a time when there had been persistent rain for many

days and some of the roofs had become waterlogged. This was seen on the Rossetti-Bau

building (Fig. 15 and 16) where pools of water provide temporary additional habitats for wildlife

and can act as bathing and drinking water for birds.

The authority of Basel began a campaign in 1996 to support green roofs by informing

architects, planners and the public of the ecological benefits that they bring. As a result, an

amendment was made to the building and planning law and developers are now required to use

green roofs on all new buildings with flat roofs (2). Stephan advises architects on how to design

the roofs to be of most benefit to wildlife, for example by varying the substrate depths.

Figure 15 Rossetti-Bau, viewed from roof of hospital (Taken 8th September 2003)

Figure 16 Water-logging on Rossetti-Bau (Taken 8th September 2003)


18

5 REVIEW OF PREVIOUS STUDIES 5.1 Research in Switzerland

Brenneisen (2001) was the first to carry out the first detailed ecological research on green

roofs. The study is the most comprehensive to date and it provides clear evidence that green

roofs can be of benefit to biodiversity, if designed appropriately. This has helped influence the

progress of establishing green roofs as an integral part of urban planning in the UK.

A translation was made of Brenneisen’s study for this project. The spider, beetle and bird

species using green roofs in Basel and Lucerne were surveyed over four years. 254 species of

beetle and 74 species of spider were recorded, many of which are rare (3). It was found that the abundance of invertebrates means that these roofs provide a

beneficial habitat for birds. In 250 hours of observation, 1304 sightings were made on 16 green

roofs between April and October in 1999 in Basel. 70% of these sightings involved a specific

activity which included (in order of frequency): foraging for insects, grooming, foraging for

seeds, searching for nest material, roosting and singing. 81.3% of the duration of all activities

was involved in using the resources of the roof, with searching for food the predominant activity.

25 species were recorded, with house sparrows, white wagtails, black redstarts and feral

pigeons most frequently observed. The use by black redstarts is of particular interest to efforts

in the UK to conserve this bird (see Section 3.3). Along with the three other species mentioned,

the black redstart is normally found on open, less vegetated ground and its presence in an

urban environment was surprising. Sightings of more common urban species such as

blackbirds and tits were much less frequent, which highlights the fact that birds use green roofs

selectively according to their individual preferences.

A key finding was the difference in the amount of bird activity seen at varying locations.

Roofs located closer to agricultural land in the suburbs were less frequently used than those in

the city centre apparently due to the provision of green space and food in a normally barren

urban environment. Brenneisen’s report also refers to a number of species in Germany and

Switzerland that regularly use green roofs for breeding. The crested lark, lapwing, skylark, little

ringed plover, common tern, wheatear, meadow pipit and greenfinch all take advantage of the

less disturbed environment of green roofs.

From his observations, Brenneisen was able to determine how green roofs could best be

designed to benefit wildlife. The study concluded that:

• A landscaped surface allowed the development of the most favourable habitat conditions.

• Areas of little vegetation are important for certain species.


19

• Natural soil should be incorporated with the substrate, allowing for rapid colonisation.

• Certain areas should retain water during dry periods.

• The provision of large stones and pieces of timber added to the roof humidity which

benefited spiders and beetles. Birds were also able to use these features to perch on and

benefit those with specific hunting strategies.

Due to lack of research undertaken in the UK, the report by English Nature (20) is based

largely on Brenneisen’s work. It identifies the potential relevance of green roofs to the UK and

Local Biodiversity Action Plans. Of the 25 animal species, 9 are birds: the kestrel, song thrush,

goldfinch, greenfinch, house martin, swallow, pied wagtail, black redstart and house sparrow.

5.2 Relevance of study There had been no research into the activities of birds on green roofs in the UK prior to

this study. Given the increasing number of birds that are of high conservation concern, their

use of vegetated roofs demonstrates how artificial habitats can contribute to their preservation.

Many ecologists have noted the need for further research into the biodiversity of green

roofs (17, 28, and 20). This project focuses on the use of roofs by birds, but the results are of

general importance and will provide another tool in the campaign to get green roofs established

in the UK.


20

6 SITE SELECTION

Two sites were selected to compare bird activity on green roofs in different locations and

at different stages of maturity. From the work of Stephan Brenneisen and communication with

Dusty Gedge, it was expected that a large, newly constructed roof in a rural setting (Rolls

Royce) would show much less activity than an established suburban development with small

roofs (The Diggers).

The timing of the project coincided with the opening of the new Rolls-Royce factory near

Chichester in West Sussex (Fig. 17). The site has the largest area of green roofing in the UK

and with no research having been undertaken into any aspect of the roof, it was of particular

interest to those currently involved in green roof research and promotion. It is fortunately within

driving distance of my home town of Brighton and observations of the roof began in mid-January

2004.

There was very little bird activity observed during the first four trips to the site. This is a

significant finding in line with predictions. A second comparative site was needed and, after

further research, it was discovered that green roofs were used on a group of residential houses

in Brighton called The Diggers. After obtaining permission from the residents, observations

began at the site in late February 2004 and continued until mid-April.

Figure 17 Location map of study sites (Ordnance Survey Get-a-map, 2004 http://www.ordnancesurvey.co.uk/oswebsite/getamap)


21

6.1 Site 1 – Rolls-Royce factory Grid reference: SU 884065

Figure 18 Ordnance Survey map showing location of Rolls-Royce factory (EDINA Digimap)


22

The Rolls-Royce factory is situated in the grounds of the Goodwood estate, just outside

Chichester in West Sussex (Fig. 18, 22 and 23). BMW (who own Rolls-Royce) decided to

locate their new factory here mainly because of the short distance to Southampton Docks where

new cars are exported from, but also because Goodwood is the home of British motor racing.

The manufacturing plant and head office have been built on the site of a former gravel

pit. Construction work began in July 2001 with the Grand Opening in May 2003. As the estate

is within an Area of Outstanding Natural Beauty, a large amount of money (£65 million) was

spent in making the factory blend in with the surroundings. Nicholas Grimshaw, architect of the

Eden Project in Cornwall, designed the buildings to be partially sunk into the ground and

covered with vegetation (22).

An extensive green roof covers a total of approximately 33,000m2, the largest area of

vegetated roof in the UK (33). Six varieties of sedum have been hydro-seeded, i.e. the seed,

fertiliser, fibre mulch and water are blended together and sprayed onto the roof in one

application. This method provides the seeds with a blanketing coat that retains water, while

providing protection from sunlight and wind. When germination begins, the fibre mulch slowly

decomposes and adds nutrients to the growing medium. Three inches of crushed brick has

been used for the substrate.

Landscape work

was completed in

January 2004 and at

present, the factory is still

viewable from a distance

(Fig. 20). The 400,000

newly planted saplings

will in time help disguise

the site, along with the

establishment of the roof

vegetation which will

make it ‘greener’ (Fig.

19).

Figure 19 Plan of the Rolls-Royce factory (44)


23

Figure 20 Rolls-Royce factory from the east (Taken 7th April 2004)

Figure 21 Roof of Rolls-Royce factory (Taken 14th April 2004)


24

Figure 23 Aerial photograph showing location of Rolls-Royce factory (close-up) (Getmapping, 1999)

Figure 22 Aerial photograph showing location of Rolls-Royce factory (distant) (Getmapping, 1999)


25

6.2 Site 2 – The Diggers Grid reference: TQ 315072

Figure 24 Ordnance Survey map showing location of The Diggers (EDINA Digimap)


26

The Diggers is situated near Hollingbury, on the outskirts of Brighton (Fig. 24, 28 and 29).

It is a group of nine houses that were built under a self-build co-operative scheme that followed

the Walter Segal approach to construction (13). Starting in 1992, members of the scheme each

worked a total of 24 hours per week until work was completed in 1994. The greenfield land was

bought from the local council and work was funded by South London Family Housing

Association (44). To overcome planners’ concerns about the density of houses on the site,

green roofs were included in the design, which increased the grassed area and reduce the

visible building density. Figures 25, 26 and 27 show various views of the site.

The total area of green roofing is around 900m2. Two inches of topsoil were laid with a

mixture of sedum and wildflower seed and after ten years, the vegetation is well-established.

Figure 25 The Diggers from the south (Taken 1st February 2004)


27

Figure 26 View of houses 5 and 6 of The Diggers from the north (Taken 1st February 2004)

Figure 27 Houses 5 and 6 of The Diggers (Taken 18th April 2004)


28

Figure 29 Aerial photograph showing location of The Diggers (close-up) (Getmapping, 1999)

Figure 28 Aerial photograph showing location of The Diggers (distant) (Getmapping, 1999)


29

7 METHODS

Observations began in mid-January and ended in mid-April 2004. By choosing these

months, both visiting winter birds and the arrival of migratory birds could be viewed as well as

changes in activity associated with the start of the breeding season. Each visit to the Rolls-

Royce factory or The Diggers involved an observation period of one hour. Twelve hours were

spent at each site, which covered six morning and six afternoon observation periods. Early

morning and late afternoon are the times when birds are most active (Gedge, pers. com, 2003).

Morning observation periods were made for one hour between 7am and 10am. Afternoon

observations were made approximately one hour before sunset. This was between 2pm and

3pm before British summer time began (28th March 2004) but changed to between 5pm and

6pm after this date when the days became longer. Every effort was made to follow this

timetable accurately, but there were times when bad traffic meant observations at Rolls-Royce

varied slightly.

There was no access to the Rolls-Royce roof without the use of a cherry picker and the

roofs of The Diggers are too small to allow observations to take place on them without

disturbing the birds. Instead, viewing took place from an embankment at the factory and from

the communal garden at The Diggers (Fig. 30 and 33). These positions allowed the birds to be

viewed at a distance using binoculars without disturbing their natural behaviour (Fig. 31, 32, 34

and 35).

During the observation hour, the bird species, its activity and the duration of the activity

was noted. Activities were separated into the following categories:

• Foraging or feeding

• Collecting nest material

• Passive (on vegetation)

• Passive (on edge)

The last two categories group those activities which did not involve using the resources

provided by the roof’s vegetation. These activities are likely to also occur on unvegetated roofs,

but because a connection with the existence of vegetation is possible, they were included in the

investigation.

A note was also made of those birds present in the area, but who were not using the

roof. This helped identify the reasons why the roofs were not of benefit to these species and

whether there is the potential for this to change.


30

N

Figure 30 Viewing position at the Rolls-Royce factory

Figure 32 Viewing position from the southeast (Taken 19th February 2004)

Figure 31 View from position on embankment (Taken 19th February 2004)


31

Figure 33 Viewing position at The Diggers

N

Figure 35 Viewing position from the north (Taken 24th March 2004)

Figure 34 View from position in communal garden (Taken 24th March 2004)


32

8 LIMITATIONS

The main limitation was not being able to view the whole roof at either site. Due to the

size of the Rolls-Royce roof, and the location of the viewing position, only approximately

7,500m2 could be seen of the 33,000m2 roof. At The Diggers, the slope of the land meant only

the roofs of houses 1-4 could be viewed, which is approximately 320m2 of the 900m2 total area.

Although a view of the total roof area would have been ideal, the observations that were made

are representative of the whole roof.

Time was also a limiting factor. Three or four hours a week were spent at the sites,

limited by course commitments and the journey time of an hour to get to the Rolls-Royce

factory. However, the observation periods were regular and carefully timed so they would

produce representative results.

The study is therefore a ‘snapshot’ of bird activity on green roofs. With a limited amount

of data, statistical analysis of the results was restricted but credible descriptive analysis could be

made. Also, observations are limited to single morning and afternoon periods rather than at

more frequent intervals.

Birds were chosen as the focus of this study as identification is relatively straightforward.

However, there were a few occasions where a bird could not be identified in the field and a

photograph was taken using a digital camera through the binoculars. Dusty Gedge was then

able to help with identification.


33

9 RESULTS 9.1 Summary • A total of 24 hours was spent bird watching; 12 hours at each site.

• A total of 121 visits were made by the birds; 25 at Rolls-Royce and 96 at The Diggers.*

• A total of almost 6.5 hours of bird activity was observed; 39 minutes at Rolls-Royce and 5

hours 48 minutes at The Diggers.+

• 14 different bird species were observed; 6 at Rolls-Royce and 8 at The Diggers.

• 4 red list species were observed; 2 at Rolls-Royce and 2 at The Diggers. • 3 amber list species were observed using the vegetation; two at Rolls-Royce and one at

The Diggers. • 2 species observed are ‘priority species’ in the UK and 2 are ‘priority species’ in Sussex. • 70% of the total activity duration at both sites used the resources provided by the

vegetation i.e. seeds and insects for food, and plant debris for nest material.

* A bird landing on the roof, carrying out an activity and then leaving is classed as one visit. + The total duration of activity at both sites is a total of each individual bird’s activity i.e. if two birds fed on

the roof together for two minutes, the total duration of activity would be four minutes.

The colour-coding on the following tables and pie

charts refer to the RSPB’s report ‘The population

status of the birds in the UK: Birds of conservation

concern 2002-2007’ (2002), explained in Section 3.1.

Observation period numbers (Fig. 36 and 41) refer to the log made of all bird activities (see

appendix, Section 13.1 and 13.2)

Key to charts

Red list species Amber list species Green list species


34

9.2 Rolls-Royce

Observation Period

Jan

Feb

Mar

April

Species

2 3

5

6

7

8

9

10

11

12

13

14

Total No.

Visits

% of Grand Total

Linnet (Carduelis cannabina)

0

0

0

0

0

0

0

4

0

0

1

0

5

20

Song thrush (Turdus philomelos)

0

0

0

0

1

0

0

0

0

0

0

0

1

4

Common gull (Larus canus)

0

0

3

0

0

0

0

0

0

0

0

0

3

12

Ringed plover (Charadrius hiaticula)

0

0

0

0

0

0

0

0

0

1

0

1

2

8

Pied wagtail (Motacilla alba)

0

0

0

5

8

0

0

0

0

0

0

0

13

52

Rook (Corvus frugilegus)

1

0

0

0

0

0

0

0

0

0

0

0

1

4

Total No. Visits

1

0

3

5

9

0

0

4

0

1

1

1

25

100

KEY

Morning observation period

Afternoon observation period

Time Spent in Activities (secs)

Species Feeding/ Foraging

Collecting

nest material

Passive

(on vegetation)

Passive

(on edge)

Total Time

(mins)

% of

Grand Total

Linnet (Carduelis cannabina)

40

150

190

0

6

16

Song thrush (Turdus philomelos)

180

0

0

0

3

8

Common gull (Larus canus)

180

0

360

0

9

23

Ringed plover (Charadrius hiaticula)

40

0

800

0

14

36

Pied wagtail (Motacilla alba)

224

0

0

130

6

16

Rook (Corvus frugilegus)

10

0

0

0

0.2

1

Total Time (mins)

11

3

23

2

39

100

% of Grand Total

28

8

59

5

100

Figure 36 Number of visits each species made to the Rolls-Royce factory

Figure 37 Time spent by each species in specific activities at the Rolls-Royce factory


35

86% of the total duration of all activities at Rolls-Royce involved species of moderate or

high conservation concern. Of the six species seen to be using the roof, two are on the red list.

A pair of linnets were seen on two occasions and one individual seen on another during April.

Similar time was spent in collecting nest material as in passive activity on the vegetation. While

the pair were on the roof, one individual would search and collect nest material while the other

would remain still and scan. The song thrush is the other red list species that used the roof,

albeit briefly. One individual was seen feeding for three minutes on one occasion during

February. Both the linnet and the song thrush are part of the UK BAP, and the song thrush is

also part of the Sussex BAP.

Pied wagtail 52%

Linnet 20%

Common gull 12%

Ringed plover 8%

Rook 4%

Song thrush 4%

Figure 38 Species at the Rolls-Royce factory - Proportion of visits by each species as a percentage of the total number of visits (Data from Fig. 36)

Total number of visits = 25


36

Two amber list species were also observed. Three common gulls were seen on one

occasion in January. Two members of the group rested on the vegetation while one individual

fed for three minutes. This accounted for the second highest proportion of the total duration of

activities by all species, after the ringed plover (Fig. 39).

One ringed plover was observed on two occasions in late April (the start of the breeding

season). This accounted for 8% of the total number of visits, but the bird spent the longest

duration on the roof compared to the other species (Fig. 39). The bird was seen nesting for

over 13 minutes. On one occasion, it was discovered resting on the roof at the start of an early

morning observation period, suggesting it may have been there for some time.

The two other species were green list birds. Pied wagtails visited the roof more often than

any other species, accounting for over half the total number of visits (Fig. 38) but these visits

Ringed plover 36%

Common gull 23%

Linnet 16%

Pied wagtail 16%

Song thrush 8%

Rook 1%

Total duration of all activities = 39 mins

Figure 39 Activity duration at the Rolls-Royce factory - Proportion of time each species spent in activities as a percentage of the total duration of all activities (Data from Fig. 37)


37

were short in duration and the species accounts for a much lower proportion (16%) of the total

duration of all activities. Pied wagtails were only seen in January and February and spent most

of their time foraging or feeding.

When looking at how the roof was used by all species (Fig. 40), 95% of activity duration

was spent on or using the vegetation. 36% of activity duration was spent using the resources of

the vegetation itself, i.e. for feeding or collecting nest material. Passive use of the vegetation

accounts for nearly 60% of the total duration of activity. This is largely due to the ringed plover

which used the roof as nesting ground. Nearly 30% of the activity duration involved foraging for

food, mainly by pied wagtails.

Other species were seen in the surrounding area, but not using the roof itself. Skylarks (a

red list species) were heard on most occasions from the farmland behind the embankment.

Passive (on vegetation)

59%

Foraging or feeding 28%

Collecting nest material

8%

Passive (on edge) 5%


Figure 40 Activity at the Rolls-Royce factory - Proportion of time all species spent in each activity as a percentage of the total time (Data from Fig. 37)


38

Flocks of meadow pipits (an amber list species) were often seen in the tress along the

embankment and flying overhead. On one occasion, a flock of around 10 yellowhammers

(which are on the red list) flew overhead and later landed in the surrounding shrubs.


39

9.3 The Diggers

Observation Period

Feb

March

April

Species

1 2

3

4

5

6

7

8

9

10

11

12

Total No.

Visits

% of grand total

House sparrow (Passer domesticus)

0

0

0

1

0

0

0

0

2

2

0

0

5

5

Starling (Sturnus vulgaris)

3

2

9

0

0

2

2

3

12

0

0

7

40

42

Herring gull (Larus argentatus)

0

0

0

0

0

0

1

0

0

0

0

0

1

1

Blackbird (Turdus merula)

0

0

0

0

1

0

0

0

0

0

0

0

1

1

Collared dove (Streptopelia decaocto)

0

4

1

3

0

0

1

0

1

0

0

0

10

11

Greenfinch (Carduelis chloris)

0

0

0

0

0

1

0

0

0

0

0

0

1

1

Magpie (Pica pica)

0

2

1

0

0

0

1

1

0

1

2

1

9

9

Wood pigeon (Columba palumbus)

1

6

3

3

0

3

2

3

4

3

0

1

29

30

Total No. Visits

4

14

14

7

1

6

7

7

19

6

2

9

96

100

KEY

Morning observation period

Afternoon observation period

Figure 41 Number of visits made by each species to The Diggers


40

Time Spent in Activities (secs)

Species Feeding/ Foraging

Collecting

nest material

Passive

(on vegetation)

Passive

(on edge)

Total Time

(mins)

% of

Grand Total

House sparrow (Passer domesticus)

70

0

0

120

3

0.5

Starling (Sturnus vulgaris)

5460

250

0

10

95

28

Herring gull (Larus argentatus)

0

0

0

30

0.5

0.2

Blackbird (Turdus merula)

0

0

10

0

0.2

0.1

Collared dove (Streptopelia decaocto)

2430

0

420

3450

105

30

Greenfinch (Carduelis chloris)

30

0

0

0

0.5

0.2

Magpie (Pica pica)

250

195

0

40

8

2

Wood pigeon (Columba palumbus)

6670

0

270

1110

134

39

Total Time (mins)

249

7

12

79

347

100

% of Grand Total

72

2

3

23

100

Figure 42 Time spent by each species in specific activities at The Diggers


41

Two of the eight species seen at The Diggers are red-listed. Starlings were active for

the whole three-month observation period and account for the largest number of visits (Fig. 43),

although the duration of each visit was shorter than those made by wood pigeons, the next most

frequent visitor (Fig. 44). The starlings used the roof mainly for feeding, but also began

collecting nest material in the spring months. On one occasion, a pair were seen to mate on the

roof of house number 7 in late March, although this is not included in the results as observations

focused on the roofs of houses 1 to 4. House sparrows were the other red list species seen using the roof, although only for a

relatively short period of time (0.5% of the total duration of activity seen at The Diggers, see

Fig.44). The majority of its time was spent perched on the edge of the roof, but on a few

occasions an individual moved across to feed.

Figure 43 Species at The Diggers - Proportion of visits by each species as a percentage of the total number of visits (Data from Fig. 41)

Starling 42%

Wood pigeon 30%

Collared dove 11%

Magpie 9%

House sparrow 9%

Blackbird 1%

Greenfinch 1%

Herring gull 1%

Total number of visits = 96


42

A herring gull (an amber list species) was seen once at rest on the edge of the roof for

30 seconds. The remaining five species observed are green-listed birds. Wood pigeons and

collared doves accounted for nearly 70% of the total activity duration (Fig. 44). Both species

were active throughout the three months, spending a high proportion of time feeding but on

some occasions using the roof as a roosting ground. They were also seen resting on the edge

of the roof for long periods of time.

Magpies were the fourth most frequent visitor (Fig. 43) that used the roof for both

foraging and collecting nest material. Other species were noticeably aware of their presence

and were often scared off by a magpie flying overhead.

Figure 44 Activity duration at The Diggers - Proportion of time each species spent in activities as a percentage of the total duration of all activities (Data from Fig. 42)

Wood pigeon 39%

Collared dove 30%

Starling 28%

Magpie 2%

House sparrow 0.5%

Greenfinch 0.2%

Herring gull 0.2%

Blackbird 0.1%



43

A blackbird was observed on one occasion, using the roof as a resting ground for a few

seconds. A greenfinch also made a brief visit, but used the roof to feed.

Figure 45 shows that when comparing how the roof was used by all species, foraging

and feeding accounted for 72% of the total duration of activities, mainly by collared doves, wood

pigeons and starlings.

Other species observed in the area but not using the roofs were crows, blue tits and

robins. A species of woodpecker was also heard in the surrounding trees during one

observation period.

Foraging or feeding 72%

Passive (on edge)

23%

Passive (on vegetation)

3%

Collecting nest material 2%

Figure 45 Activity at The Diggers - Proportion of time all species spent in each activity as a percentage of the total time (Data from Fig. 42)



44

10 DISCUSSION

The results of this study demonstrate the current value and the conservation potential of

green roofs for birds. A significant amount of activity was observed in just 24 hours of bird

watching, and much of this involved highly or moderately threatened species. 70% of the total

duration of all activities observed at both sites involved the use of resources provided by the

vegetation itself.

10.1 Rolls-Royce

The factory roof attracted four species of conservation concern, which accounted for

83% of the total duration of all activities. The roof is formed of a well-drained, low nutrient

substrate which is similar in character to vegetated shingle (Fig. 46), heathland and brownfield

habitats. The pied wagtail, linnet, common gull and ringed plover seen using the roofs are all

species associated with these habitats.

At its present immature stage,

the roof is not attracting seed-eating

birds such as corn and reed

buntings (UK BAP species),

yellowhammers and finches. As

plants become more established,

the roof will provide more food for

these species. Yellowhammers, a

red list species due to the rapid

decline in the breeding population

over the past 25 years, were seen in

the area and are potential users of

the roof in the future. The

increasing abundance of insects is

also likely to attract other species observed in the surrounding area such as meadow pipits and

skylarks.

The song thrush (Turdus philomelos) (Fig. 47) is on the red list and is a UK and Sussex

BAP species which has experienced a rapid decline in recent years. The reasons for the

decline are not fully understood, but fox and corvid predation, competition with blackbirds and

changes in farming methods which affect the availability of nest sites are thought to be major

Figure 46 Vegetated shingle at Dungeness, Kent (50)


45

reasons (26). It was foraging at Rolls-Royce briefly

but is likely to find the roof more beneficial as a

feeding ground once more vegetation has become

established and there are greater numbers of

invertebrates.

The sighting of the ringed plover (Charadrius

hiaticula) at Rolls-Royce (Fig. 48 and 49) is of great

significance, not only because of the bird’s

conservation status, but also because the factory is

located 10km from the sea. This bird breeds on

shingle beaches and also inland in sand and gravel pits or former industrial sites with bare

ground (34). It is an amber list bird, previously as a result of its European status but recent

winter declines means the species now meets a second criterion (5). Like other coastal ground-

nesting birds, the ringed plover is very vulnerable to disturbance. It was seen at rest on the

factory roof and circling the area. As it was the start of the breeding season, this could suggest

that nesting areas were being explored.

Figure 49 Ringed plover on roof of Rolls-Royce factory (Taken at 8am on 14th April 2004)

Figure 48 Ringed plover Taken by Hugh Harrop (59)

Figure 47 Song thrush (54)


46

Following the work of Brenneisen (3), it would be expected that a roof of similar design

and size in a coastal town, for example Shoreham, would be of benefit to a larger number of

ground-nesting sea birds, especially little terns and oystercatchers which are affected by

mammalian predation and high tides. However, no study on green roofs in coastal locations

have been undertaken. Brenneisen’s report referred to certain species known to use green

roofs for breeding, including lapwings, skylarks and meadow pipits (Fig. 56). Birds have also

been sighted nesting on the vegetated roof of the Ecover factory in Belgium, including a falcon

(36).

Linnets (Carduelis cannabina) are very important brownfield species, seen foraging and

collecting nest material on the roof in April (Fig. 50 and 51). The bird is on the red list and is a

UK PRIORITY species as it has seen a decline in population of over 50% in the last 25 years.

Nest failure rates were high in the mid-1970s and it is thought this is still the case, largely due to

reductions in hedgerow which leaves nests more exposed and at greater risk from predation (4). It is found in a range of habitats, including heathland, lowland farm and city centres. In London,

linnets are encountered on brownfield land and have been observed feeding on sedums of

spontaneous green roofs and on moss-covered gutters (Gedge, pers. com, 2004).

Figure 50 Pair of linnets on roof of Rolls-Royce factory (Taken at 8.45am on 7th April 2004)

Figure 51 Linnet (55)


47

Despite its name, the common gull (Larus

canus) (Fig. 52) is rare in some inland areas,

although still abundant on the coast. Its amber

list status is a result of its unfavourable

conservation status in Europe (a SPEC 2

species), a moderate decline in its breeding

population in the last 25 years and more than

50% of the population occurring in 10 or fewer

sites in the UK (40). It was observed feeding briefly on the roof

of Rolls-Royce, but as with the ringed plover, it

could potentially use it as a nesting ground as it

prefers elevated sites.

Pied wagtail (Motacilla alba) populations in the UK are augmented by migrants from

Northern Europe during the winter. The bird was only observed in January and February which

suggests that those observed were likely to be wintering birds from continental Europe.

The presence of the ringed plover suggests that it could even be possible for rare and

priority species such as the stone curlew to be attracted to such roof habitats to nest. This

species is associated with stony heathland and farmland and once bred extensively on the

vegetated shingle bank at Dungeness in Kent. This population crashed due to fox predation. A

roof of a large enough size in a rural setting such as Rolls-Royce would provide a suitable

nesting ground with the advantage of relative safety from mammalian predation (Gedge, pers.

com, 2004). Furthermore, if green roofs were designed with a species’ nesting ecology in mind,

they could provide mitigation for new urban developments (as in the case of the black redstart in

London). There is currently a problem in South Wales with breeding populations of lapwings

occuring on sites to be developed. Lapwings are known to breed on green roofs in Germany

and so it is thought that providing vegetation on the new developments could lessen the

ecological impact. A roof in Carmarthen is at present being designed to provide nesting habitat

for lapwings in a rural location (Gedge, pers. com, 2004).

Figure 52 Common gull (58)


48

10.2 The Diggers

As expected, more activity was observed at The Diggers compared to Rolls-Royce due to

its suburban location. However, there was much less use by birds of conservation concern,

who accounted for just under 29% of the total duration of all activities. The mix of sedum and

wildflower used on the roofs means they most closely resemble an unmaintained amenity

grassland.

House sparrows (Passer domesticus) (Fig.

53) were seen to briefly use the roof of The

Diggers to feed. It is a red list species as the

breeding population has seen a decline of more

than 50% in the last 25 years. Reductions in

insect abundance, changes in agricultural

practices and changes in roof design are just

some of the factors put forward to explain the

decline, but it remains unclear which is having

the most effect (31). They have become far less

common in city centres and in the suburbs and

are subsequently part of the London BAP.

Brenneisen’s study found the species to be one of the most frequent users of green roofs.

As noted in English Nature’s report (20), green roofs in urban areas could provide alternative

feeding ground for house sparrows. Nesting sites could form part of the design of new buildings

or could even be retro-fitted into existing structures.

Starlings (Sturnus vulgaris) were frequent users of the roofs to feed and occasionally

collect nest material (Fig. 54 and 55). Like the house sparrow, they are new to the red list due

to the recent rapid decline in their population. Permanent pasture is the species’ preferred

feeding habitat and with the general intensification of livestock rearing, there have been major

adverse effects on farmland populations (7).

The sighting of the amber-listed herring gull (Larus argentatus) was very brief and did not

utilise the vegetation on the roof, making this observation insignificant. Although the green list

species observed at both sites are not presently of conservation concern, their status may

change in the future. The frequency of use by wood pigeons (Columba palumbus), collared

doves (Streptopelia decaocto), pied wagtails (Motacilla alba) and magpies (Pica pica) observed

Figure 53 House sparrow Taken by Mike Lane (74)


49

in this project demonstrate the huge benefits green roofs have for these species as areas for

feeding and resting.

As demonstrated in Brenneisen’s research, the potential of green roofs depends on their

location. Vegetated roofs in the centre of Basel in Switzerland attracted birds from open

landscapes such as high mountain areas or river banks. A study by Savard et al. (42) found

that the amount of existing vegetation in an urban area is proportional to the diversity of birds

found within urban areas. The numbers and diversity of migratory birds found in cities is also

proportional to the abundance of vegetation. Considering the amount of activity observed on

both a rural and suburban green roof during this study, it would be expected that if placed in an

urban setting, they would be of even greater benefit.

Green roofs can be designed to help meet targets of the previously mentioned BAP

species. Coastal vegetated shingle, lowland calcareous grassland, lowland meadows and

lowland heathland are all Priority Habitats in the UK BAP, and are important for a number of red

and amber list bird species. Although green roofs should not be viewed as a substitute for the

Figure 54 Starling and wood pigeon on roof of The Diggers (Taken at 6.30pm on 15th April 2004)

Figure 55 Starling Taken by Sue Tranter (49)


50

displaced natural habitat, they do provide some compensation for biodiversity if substrate type,

substrate depth and vegetation type are carefully planned.

Considering the amount of money bird organisations such as the RSPB spend on

protecting ground-nesting birds, for example in controlling fox numbers and installing electric

fencing, green roofs seem a much cheaper and more effective alternative for at least reducing

the threat. Aerial predation however is a threat that cannot be avoided. It may even be

increased as foraging or nesting birds on roofs are more exposed than on the ground where

natural features can act as shelter. It was noticed at The Diggers that magpies (a known

predator of smaller birds) flying overhead or landing on the roof would scare away starlings and

other species. The UK population of sparrowhawks is increasing rapidly after the steep decline

in numbers caused by the use of pesticides in the 1950s and 1960s (6). Predation by these and

other raptors can be taken into account when designing new green roofs or improving existing

ones by providing structures or small shrubs that act as cover.

Many European cities have a more sustainable approach to development compared to the

UK. Like Basel in Switzerland, Linz in Austria has a widespread green roof programme. Since

the 1980s, the city has subsidised the installation of green roofs, paying for 35% of the cost (1). There is huge potential for establishing green roofs in the UK. It is estimated that 200 million m2

of existing roofs in UK cities could be vegetated with little or no modification to the building’s

structure (20). Green roofs could become more commonplace with further research and

promotion of their benefits. The advantages to birds have been demonstrated through this

project.


51

Conservation Status

Potential use of

green roofs

Species

UK BAP

Red List

Amber

List

Protected Species

Feeding

Nesting

Known on

green roofs in

continental Europe

Black Redstart Phoenicurus ochruros

x x x x

Common Tern Sterna hirundo

x x

Corn Bunting Miliaria calandra

x x x

House Sparrow Passer domesticus

x x x

Lapwing Vanellus vanellus

x x x x

Linnet Carduelis cannabina

x x x

Little ringed plover Charadrius dubius

x x x x

Little Tern Sterna albifrons

x x x

Meadow Pipit Anthus pratensis

x x x x

Oystercatcher Haematopus ostralegus

x x x

Ringed Plover Charadrius hiaticula

x x x

Skylark Alauda arvensis

x x x x x

Song Thrush Turdus philomelos

x x x

Starling Sturnus vulgaris

x x

Stone Curlew Burhinus oedicnemus

x x x x

Tree Sparrow Passer montanus

x x

Wood Lark Lullula arborea

x x x x

Yellow Wagtail Motacilla flava

x x x

Figure 56 Summary table of bird species that could benefit from green roofs. The grey highlights those birds observed using roofs in this study.


52

11 CONCLUSION

Green roofs have huge potential to aid bird conservation efforts in the UK. The two roofs

studied for this project were of different size, design and location and were not installed

specifically to benefit birds, yet a high amount of activity was observed, especially by birds of

conservation concern. If green roofs were to be designed to meet the needs of threatened

species, then the activity is expected to be even higher. New projects in the Deptford area of

London have already been established to help the rare black redstart. They have demonstrated

what can be achieved for wildlife and a further 250,000 m2 of green roofing designed specifically

for this bird has been planned.

Their potential of green roofs depends on their location, with more species likely to benefit

from those in an urban environment. Due to the dynamic nature of urban ecosystems, a small

effort in management can have a significant impact on bird abundance and diversity. Green

roofs need the backing of the Government to become a component of urban planning, as in

other European cities. Bringing a natural element into the urban environment will be of great

benefit, not just to birds, but to other wildlife and humans.

Although this is a small-scale project, the results are of high significance and have

provided baseline data to be published on livingroofs.org, the first independent UK website to

specifically promote green roofs. Further research is needed on how birds use green roofs in

different locations. Observations have continued during May at the Rolls-Royce factory by an

ornithologist and I intend to make regular trips throughout the summer of 2004.


53

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3) Brenneisen S (2001) ‘Vogel, Kafer und Spinneren auf Dachbegrunungen –

Nutzungsmoglichkeiten und Einrichtungsoptimeierungen’ Geographisches Institut Universitat Basel/Baudepartment des Kantons Basel-Stadt, Basel

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website http://www.bto.org/birdtrends/wcrrinpl.htm (Accessed 24/4/04)

6) British Trust for Ornithology (BTO) (2004) ‘Sparrowhawk: Accipiter nisus’ BTO website http://www.bto.org/birdtrends/wcrsparr.htm (Accessed 24/4/04)

7) British Trust for Ornithology (BTO) (2004) ‘Starling: Sturnus vulgaris’ BTO website

http://www.bto.org/birdtrends/wcrstarl.htm (Accessed 24/4/04)

8) Box J, Shirley P (1999) ‘Biodiversity, brownfield sites and housing’ Town and Country

Planning, 68, 306-309 9) Chamberlain DE, Fuller RJ (2000) ‘Local extinctions and changes in species richness of

lowland farmland birds in England and Wales in relation to recent changes in agricultural land-use’ Agriculture, Ecosystems and Environment, 78, 1-17

10) Chipchase A, Frith M (2002) ‘Brownfield? Greenfield? The threat to London’s unofficial

countryside’ Report by London Wildlife Trust 11) Collins P (Undated) ‘Green roofs and earth sheltered buildings’ Nottingham Trent

University website http://construction.ntu.ac.uk/staffwebs/greenroofs/aboutGRandESB.htm (Accessed 17/5/03)

12) Department of the Environment, Transport and the Regions (DETR) (1999) ‘Projections

of households in England to 2021’ 13) Design for Homes (2003) ‘Diggers, Brighton’ Design for Homes website

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14) Doody JP (2003) ‘Guidance for the management of coastal vegetated shingle’ English Nature website http://www.english-nature.org.uk/livingwiththesea/project_details/good_practice_guide /shingleCRR/shingleguide/home.htm (Accessed 20/4/04)

15) English Nature (2004) ‘Biodiversity Action Plans: lowland heaths’ http://www.english-nature.org.uk/baps/habitats/bap3.htm (Accessed 20/4/04)

16) Frith M, Farrell J (2003) ‘Green roofs and the urban renaissance in Britain’ Report for the First North American Green Roof Infrastructure Conference, Awards and Trade Show 30th/31st May 2003

17) Gedge D (2002) ‘Roofspace – a place for brownfield biodiversity?’ ECOS, volume 22,

Issue3/4, 69-74 18) Gedge D (2003) ‘From rubble to redstarts’ Report for the First North American Green

Roof Infrastructure Conference, Awards and Trade Show 30th/31st May 2003 19) Gedge D, Frith M, Harvey P (2002) Black redstarts website

http://www.blackredstarts.org.uk/index.html (Accessed 17/5/03)

20) Grant G, Engleback L, Nicholson B (2003) ‘Green roofs: their existing status and

potential for conserving biodiversity in urban areas’ Report 498 by English Nature 21) Greenroofs (2004) Greenroofs website

http://www.greenroofs.com (Accssed 2/3/04)

22) Glancey J (2004) ‘Buried treasure’ Guardian website 16/2/04

http://www.guardian.co.uk/g2/story/0,3604,1148883,00.html (Accessed 16/2/04)

23) Harrison C, Davies G (2002) ‘Conserving biodiversity that matters: practitioners’

perspectives on brownfield development and urban nature conservation in London’ Journal of Environmental Management, 65, 95-108

24) International Union for Conservation of Nature and Natural Resources (IUCN) (2003)

‘2003 IUCN Red List of Threatened Species’ The IUCN Species Survival Commission http://www.redlist.org (Accessed 2/4/04)

25) Joint Nature Conservation Committee (JNCC) (2004) ‘Habitat Action Plan: lowland

calcareous grassland’ UK Biodiversity Action Plan website http://www.ukbap.org.uk/ukplans.aspx?ID=12 (Accessed 20/4/04)

26) Joint Nature Conservation Committee (JNCC) (2004) ‘Species Action Plan: Song

Thrush (Turdus philomelos)’ JNCC website http://www.ukbap.org.uk/UKPlans.aspx?ID=621 (Accessed 23/4/03)


55

27) Joint Nature Conservation Committee (JNCC) (2004) ‘UK Biodiversity Action Plan: Birds’ http://www.ukbap.org.uk/SpeciesGroup.aspx?ID=7 (Accessed 2/4/04)

28) Kadas G (2002) ‘Study of invertebrates on green roofs – how roof design can maximise

biodiversity in an urban environment’ Degree thesis 29) Leech D (2002) ‘Factors affecting the survival of birds of conservation concern:

agricultural intensification’ The British Trust for Ornithology website http://www.bto.org/research/advice/birdsconconcern/bccsection522.htm (Accessed 20/4/04)

30) Livingroofs (2004) Livingroofs website http://www.livingroofs.co.uk (Accessed 7/4/04)

31) London Biodiversity Partnership (2002) ‘House sparrow’ London Biodiversity Partnership website http://www.lbp.org.uk/action/species/sapsparrow.htm (Accessed 23/4/04)

32) Madge G (2004) ‘Agricultural policy’ Broadcasted on ‘Farming Today’, BBC Radio 4,

11/1/04 33) Madslien J (2003) ‘Rolls-Royce: Technology and craftsmenship’ BBC News Online

2/1/03 http://news.bbc.co.uk/1/hi/business/2561883.stm (Accessed 17/5/03)

34) Mullarney K, Lars S, Zetterstrom D, Grant PJ (1999) ‘Collins Bird Guide’ (HarperCollins: London)

35) Palmer-Wilson K (2003) ‘Introduction to horticultural therapy and green roofs’ The Green

Roof Infrastructure Monitor, Volume 5, 1, 11-12 36) Peck SW, Callaghan C (1999) ‘Greenbacks from green roofs: Forging a new industry in

Canada’ Report by Peck and Associates for Canada Mortgage and Housing Corporation 37) Peck S, Kuhn M (Undated) ‘Design guidelines for green roofs’ http://www.cmhc-schl.gc.ca/en/imquaf/himu/loader.cfm?url=/commonspot/security/getfile.

cfm&PageID=32570 (Accessed 17/5/03)

38) Rawlinson T (2003) ‘Green Roofs’ Broadcasted on ‘You and Yours’, BBC Radio 4,

16/5/03 39) Rohrbach J (Undated) ‘The ancient world, adonis and new departures’

http://www.ecoroofsystems.com/history.html (Accessed 18/11/03)

40) RSPB (2002) ‘The population status of the birds in the UK: Birds of conservation concern

2002-2007’ Collaborative report


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41) RSPB (2004) ‘Government boost for farmland birds’ 15/4/04 http://www.rspb.org/countryside/farming/policy/index/entrylevel.asp (Accessed 20/4/04)

42) Savard JPL, Clergeau P, Mennechez G (2000) ‘Biodiversity concepts and urban

ecosystems’ Landscape and Urban Planning, 48, 131-142 43) Scholz-Barth K (2001) ‘Green Roofs: Stormwater Management From the Top Down’

Environmental Design and Construction website http://www.edcmag.com/edc/cda/articleinformation/features/bnp__features__item/0,,18769,00+en-uss_01dbc.html (Accessed 19/5/03)

44) Walter Segal Self Build Trust website (Undated) ‘Diggers, Brighton’

http://www.segalselfbuild.co.uk/projects/diggers.html (Accessed 3/2/04)

45) Woods M, McDonald RA, Harris S (2003) ‘Predation of wildlife by domestic cats in Great

Britain’ The Mammal Society website http://www.abdn.ac.uk/mammal/cat_predation.htm (Accessed 2/3/04)

46) Wong NH, Tay SF, Wong R, Ong CL, Sia A (2002) ‘Life cycle cost analysis of rooftop

gardens in Singapore’ Building and Environment, 38, 499-509 FIGURE REFERENCES 47) American Wick Drain Corporation (2004) ‘Roof garden components’ American Wick Drain

Corporation website http://www.americanwick.com/greenroof/grcomponents.html (Accessed 2/4/04)

48) Automotive Intelligence website (2000) ‘BMW: Rolls Royce Project’ http://www.autointell-news.com/european_companies/BMW/rolls-royce-project/bmw-rolls-royce-01.htm (Accessed 17/5/03)

49) BirdDiary.co.uk (2004) ‘Common starling: Sturnus vulgaris’

Photo by Sue Tranter http://www.birddiary.co.uk (Accessed 23/4/04)

50) English Nature (2003) ‘Guidance for the management of coastal vegetated shingle’

http://www.english-nature.org.uk/livingwiththesea/project_details/good_practice_guide /shingleCRR/ShingleGuide/Annexes/Annex05Dungeness/Index.htm#BirdProt (Accessed 2/4/04)

51) Gedge D, Frith M, Harvey P (2002) Black redstarts website

http://www.blackredstarts.org.uk/index.html (Accessed 17/5/03)


57

52) Livingroofs (2004) Livingroofs website http://www.livingroofs.co.uk (Accessed 7/4/04)

53) Mike Lane Wildlife Photography website (Undated) Photo by Mike Lane http://nature-photography.co.uk/Mike%20Lane.htm (Accessed 23/4/04)

54) Nature Photographers Ltd website (Undated)

http://www.naturephotographers.bramleyfrith.co.uk/separates/british/birds/bird28.htm (Accessed 23/4/04)

55) Portland Bird Observatory and Field Centre website (2002) ‘Birds’

http://www.portlandbirdobs.btinternet.co.uk/birds_may2002.htm (Accessed 23/4/04)

56) Roofscapes (2003) Roofscapes website http://www.roofmeadow.com (Accessed 2/3/04)

57) RSPB (2003) ‘Agricultural intensification and the collapse of Europe’s farmland bird

populations’ http://www.rspb.org/science/processresearch/2001/agricultural_intensification.asp (Accessed 2/3/04)

58) Rutland Water Nature Reserve website (Undated) ‘Gallery pictures: Gulls’ http://www.rutlandwater.u-net.com/rw/Gallery/RW_GalleryGulls.htm (Accessed 23/4/04)

59) Shetland Wildlife website (Undated) Photo by Hugh Harrop

http://www.shetlandwildlife.co.uk/holidays/photo/focuspics.htm (Accessed 23/4/04)

60) Short WR (2004) Hurstwic website http://www.hurstwic.org/history/articles/daily_living/text/Turf_Houses.htm (Accessed 2/3/04)


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13: APPENDIX


59

13.1 Typed log of observations at Rolls-Royce OBSERVATION PERIOD 1 – Wednesday 26th November 2003 14.00 – 15.00 • One hour visit made with Dusty and Gyongver. Met Nigel Carter, Security Manager. • Recced site and spent 20 minutes looking at roof with telescope. • Saw one pied wagtail resting on roof for roughly one minute. • Heard meadow pipits in surrounding fields. • Few more pied wagtail individuals on fence posts around us. OBSERVATION PERIOD 2 – Saturday 17th January 2004 11.30 – 12.30 Sunny, cloudless, cold, slight breeze • One rook foraging for around 10 seconds before flying off. • Low-flying aeroplanes overhead roughly every 5 minutes – possible disturbance. • Future daytime observations will not be made at the weekend when more people are flying

for leisure. • Discovered best position on bank to stand. Compromise between position of the sun and

seeing as much roof as possible. OBSERVATION PERIOD 3 – Sunday 18th January 2004 08.30 – 09.30 Sunny, cloudless, very cold, slight breeze • No birds seen on roof • Building of viewing platform may have caused some disturbance towards end of

observation period. • Allow birds to get used to platform before next visit. • 8.30am too far after sunrise – need to be there at 8am to observe possible increased dawn

activity. OBSERVATION PERIOD 4 – Wednesday 21st January 2004 15.00 – 16.00 • Dead trees being removed form the embankment – no bird watching possible. OBSERVATION PERIOD 5 – Friday 30th January 2004 10.00 – 11.00 Cold, overcast. Frozen snow patches on roof 10.22 3 common gulls on south end of roof (part of small flock in area). 2 remain still while

1 feeds. Stayed for 3 minutes before flying away.


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OBSERVATION PERIOD 6 – Thursday 19th February 2004 11.30 – 12.30 Sunny, very cold strong wind 11.35 After 5 minutes scanning, spot 2 pied wagtails in front of viewing position. Both are

dashing between the planted areas, where they stop and forage. 11.37 3 other wagtails join the pair. All 5 now feeding at planted areas.

Every few minutes, few birds drop down into gutter, for between 30 seconds and a minute, before reappearing. Gutter provides cover? Group work left to right along roof.

11.50 Wagtails still present, although not at front of roof. See the occasional ‘jump’ of a bird from over ridge of roof. Continues for further 20 minutes.

12.10 No bird activity for remaining 20 minutes. OBSERVATION PERIOD 7 – Sunday 29th February 2004 09.00 – 10.00 Cold, sunny, slight breeze • 2 skylarks active/vocal throughout hour. 09.01 1 pied wagtail lands on edge of roof and sits for 10 seconds before flying away. 09.05 1 pied wagtail (possibly same bird) lands on edge of roof. Sits and scans for around

a minute. 09.08 Flock of around 10 yellowhammers flies overhead. 09.12 Same wagtail on embankment alongside road. Chattering, occasionally feeding.

Working from left to right until out of sight. 09.31 Pied wagtail lands on roof gutter. 09.32 2 more wagtails land on roof. All 3 darting between plants and feeding for around 2

minutes. 2 leave, 1 remains feeding. Occasionally flies to next patch of vegetation, working left to right.

09.35 Wagtail goes out of sight. 2 others land on roof just out of sight. 09.45 Yellowhammer lands in tree beside me. 09.44 3 pied wagtails on far right of roof, foraging/feeding. 09.50 Song thrush lands on roof, staying for around 3 minutes. Most of time spent

scanning and darting to different areas. Feeds twice. Wagtails still foraging when I left at 10am.

OBSERVATION PERIOD 8 – Sunday 14th March 2004 08.00 – 09.00 Overcast, very strong cold wind • No birds used roof – wind too strong. • Only large birds (crows, seagulls) seen in flight. • Skylarks heard on and off throughout hour.


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OBSERVATION PERIOD 9 – Friday 26th March 2004 14.30 – 15.30 Cloudy with warm sunny spells • No birds on roof and very little activity in surrounding area. • Maintenance man on far right of roof, but too far away to have interfered with birds wanting

to visit roof directly infront of my observation point. • One skylark heard several times throughout hour, for durations of between 2-3 minutes. • Further plant growth since last visit – roof looking greener. • Flock of around 20 meadow pipits land in trees on embankment several times. OBSERVATION PERIOD 10 – Wednesday 7th April 2004 07.50 – 08.50 Cold and overcast • No sun on roof for first 40 minutes, then broke through • 2 skylarks heard in field behind throughout hour 08.40 2 linnets land on roof. Stay for 40 seconds. 1 remains still, 1 feeds. 08.43 Pair return. Again, 1 remains still and one forages. Leaves with plant material in

beak after 2.5 minutes. OBSERVATION PERIOD 11 – Tuesday 13th April 2004 17.30 – 18.30 Hazy sunshine, warm with light breeze • No birds on roof. • 2 skylarks occasionally heard in field behind throughout hour. OBSERVATION PERIOD 12 – Wednesday 14th April 2004 07.50 – 08.50 Sunny, warm with light fog • Skylarks vocal in field behind throughout hour. 07.50 Initial scan with binoculars reveals a ringed plover resting on roof towards left end.

Remains still, then darts to new area and rests again. 08.03 Plover flies off. Circles roofs while calling. 08.08 Plover lands on smaller roof to the left (where security office is located). Remains

there for 30 seconds before taking off again. Continues to circle roofs while calling for further 2 minutes.

08.45 Pair of birds land on same roof as wagtail. Too far away to identify, possibly linnets. There for 4 minutes, both feeding.


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OBSERVATION PERIOD 13 – Monday 19th April 2004 17.45 – 18.45 Sunny, strong wind • Skylarks heard throughout hour. 17.49 1 linnet lands on roof, stays for 10 seconds, then moves out of view. Its high-pitched

chirp continues for further 4 minutes. 18.08 Flock of around 25 linnets land in trees to my left on embankment. Perch for 40

seconds then fly further down embankment and land in trees. OBSERVATION PERIOD 14 – Tuesday 20th April 2004 17.50 – 18.50 Overcast, light rain, cold, light wind • Rape seed oil plant growing on far right of roof – spread from surrounding fields. • Skylark heard twice. 18.20 1 ringed plover lands on roof directly in front of me. Stays for 1 minute, spending 20

seconds stood still, and 40 seconds darting about feeding before flying off.


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13.2 Typed log of observations at The Diggers OBSERVATION PERIOD 1 – Monday 23rd February 2004 07.00 – 08.00 Sunny, very cold, light wind. • Roofs covered in icy patches. • Birds visible and active in surrounding trees. Seagulls, wood pigeons, collared doves,

blackbirds, starlings flying around, but staying in trees overlooking roofs. 07.30 More birds settling in trees. Around 50 individuals, mainly wood pigeons. 07.40 First rays of sunlight break onto roof. 07.50 Wood pigeon lands on left roof (houses 1/2). Feeding in large sunny patch.

Starlings beginning to use roofs of houses 5 and 6 to my right. Can be seen foraging at front of roof near gutter, but then go out of sight.

07.55 3 starlings land on right roof (houses 3/4). All foraging and feeding. 08.00 Pigeon and starlings fly away when a resident leaves for work. OBSERVATION PERIOD 2 – Wednesday 25th February 2004 14.15 – 15.15 Cold, cloudy with sunny spells, light wind. • Little bird activity in surrounding trees compared to morning observation period. The few

individuals present are resting on branches. • Several blue tits and robins in shrubs of communal garden. 14.25 Pair of collared doves land on right roof and start foraging/feeding. Picking up plant

debris and twigs and throwing to side to feed. 14.28 1 magpie lands on right roof. Feeds at one patch for 20 seconds then hops onto left

roof. 14.30 Resident leaves house. Magpie flies away, doves stay. Pair now on left roof

foraging and single dove on right resting on guttering. 14.31 1 starling lands on left roof and begins feeding immediately. 14.32 1 wood pigeon lands on left roof, soon followed by another. 1 dove moves back to

right roof. 14.33 Third pigeon joins 2 on left roof. All 3 foraging. 14.34 Magpie lands on left roof, collects plant material for 10 seconds and leaves. 14.35 Fourth pigeon lands on right roof. Squirrel approaches roof edge on a branch. 14.36 Second starling lands on left roof. All birds foraging/feeding. Starlings concentrate

in long grass, pigeons/doves more in short grass. 14.38 Male blackbird on ground in communal garden. 1 of 3 doves preening for 2 minutes

on right roof. 14.45 1 dove, 2 starlings still foraging on left roof, close together in patch of long grass.

Dove then roosts for 5 minutes while starlings feed around it. 14.50 Both starlings fly to trees. 1 dove left roosting on right roof. 14.55 1 pigeon lands on left roof and starts foraging. 14.56 Single dove leaves right roof (after roosting for 45 minutes). 15.08 Pigeon on left roof leaves.


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OBSERVATION PERIOD 3 – Monday 1st March 2004 07.00 – 08.00 Sunny, very cold • Roofs almost completely covered by frost. 07.00 Around 20 birds roosting in trees to right of roof. Mainly wood pigeons and starlings. 07.25 Birds becoming more active and vocal. Beginning to leave tree. 07.30 Group of starlings flies down to tree at edge of roof. 07.31 1 starling foraging along edge of roof of house 5.

Magpie in tree near roof. 07.35 1 starling lands on right roof and immediately starts feeding. 07.36 1 Wood pigeon lands on left roof and rests on edge. Second starling lands on right roof and begins foraging. 2 more pigeons land on right roof, chasing/fighting each other. 07.37 2 more starlings join right roof, quickly followed by fifth bird. All foraging. Moving

leaves and penetrating vegetation with beaks for 1 minute. 2 pigeons fighting disturb them.

07.40 1 pigeon leaves right roof, other resting on edge leaves after 20 seconds. 07.44 Magpie lands on right roof. Scanning/foraging for 20 seconds. 07.50 Starlings active on roofs of houses 5-7 but activities out of sight. 07.55 1 starling returns to feed on right roof. 07.56 3 more starlings join right roof. 07.57 Low-flying pigeon scares starlings off. 07.59 1 collared dove lands and rests on edge of left roof. OBSERVATION PERIOD 4 – Wednesday 3rd March 2004 14.00 – 15.00 Hazy sunshine, light wind, warmer than previous few days • Few birds about. 2 wood pigeons in trees to right of roofs. 14.00 1 collared dove on each roof, on edge resting. 14.03 Both doves leave. 14.05 1 house sparrow lands on left roof and feeds for 1 minute. 14.26 1 wood pigeon lands on left roof. 14.27 Second pigeon on left roof. Both feeding. Stay on same patch for 20 seconds then

move on to next. 14.29 1 pigeon moves to perch on edge and preens for 30 seconds before resuming

feeding. 14.31 Third pigeon lands on left roof and feed with other 2. 14.32 1 collared dove lands on edge of left roof. Rests/preens for 30 seconds. 14.35 1 pigeon leaves for tree to left of roof, shortly followed by other 2. 14.37 Dove leaves.


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OBSERVATION PERIOD 5 – Monday 15th March 2004 07.15 – 08.15 Foggy, light drizzle • Pairs of birds of all species squabbling/chasing each other – breeding activity. 07.15 No birds viewable in area, except 2 wood pigeons in tree to right of roofs. 07.35 Group of 5 starlings land in tree to my left then soon leave again. 07.50 Around 15 starlings return to tree to my left. Singing. 08.03 4 starlings land and feed on roof of house no.6. 08.04 2 wood pigeons land on roof of house no.5 and feed along front edge. 08.06 1 male blackbird lands on left roof very briefly, scans 10 seconds. 08.15 Wood pigeons and starlings still feeding when I leave. OBSERVATION PERIOD 6 – Wednesday 24th March 2004 14.00 – 15.00 Mixture of sunshine and showers 14.10 One starling walking on right roof for 10 seconds. Kept to edge, not on grass. 14.14 Rain starts. 14.15 1 starling, 1 pigeon feeding on left roof.

1 pigeon on right roof, resting on edge. 14.20 Starling leaves left roof, pigeon leaves right roof. 14.24 Group of starlings land on roofs of houses 5 and 6. 14.29 4 starlings feeding on front edge of house 5 for 2 minutes. 14.30 Pigeon lands and rests on edge of left roof. Other pigeon still feeding. 14.33 Greenfinch lands left roof. Forages for 30 seconds. 14.34 Pigeon stops feeding (after 19 minutes) and rests on edge of left roof. 14.37 Pigeon leaves (after 7 minutes resting). 14.52 1 collared dove feeding on edge of roof of house 5 for 2.5 minutes. OBSERVATION PERIOD 7 – Monday 29th March 2004 07.00 – 08.00 50% cloud cover, no direct sunlight on roofs. • Much bird activity/noise in trees and sky throughout hour. 07.00 Starlings feeding on roofs of houses 5 and 6 when I arrived. 07.10 Herring gull landed edge right roof. Calling for 30 seconds then left. 07.15 Woodpecker heard in trees behind roofs. 3 separate ‘knockings’. 07.17 1 wood pigeon lands on left roof and feeds for 1 minute. Scared off by birds flying

overhead. 07.24 1 collared dove searching for nest material underneath veranda of house 6 for 2

minutes. 07.25 Second dove joins first. First flies away with twig. 07.26 1 wood pigeon lands on left roof and starts feeding. 07.30 Wood pigeon moves to edge of roof to rest (after 4 minutes feeding). Rests for 20

seconds then leaves. 07.36 2 starlings mate in small tree to my left. 07.37 1 starling lands on right roof. Stays on edge, twice moving to vegetated area to feed

briefly. Stayed for 40 seconds.


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07.44 Woodpecker heard again from same position for 1.5 minutes. Continues in another tree further to left for a further 2 minutes.

07.50 Another pair of starlings mate at front of roof of house 7. 07.51 1 starling feed briefly on left roof, along with a collared dove. Both fly off after 20

seconds. 07.55 1 magpie collects nest material from right roof. Lands and leaves in 5 seconds. 07.58 Flock of 6 wood pigeons fly away from roof 5. Group may have been feeding there

for some time. OBSERVATION PERIOD 8 – Wednesday 31st March 2004 14.45 – 15.45 Sunny and warm • Little activity to start with. Increased throughout hour. • Numerous bumble bees visiting plants on roof as well as on ground. • Chat with Rosie (resident). Red plant on right roof planted by owner of house no.4 after

fire on roof caused a bare patch. Since spread to cover most of roof. 15.20 3 wood pigeons chasing each other on left roof for 1 minute. 15.24 1 starling lands on right roof to feed. 15.25 Second starling joins right roof. Both feed for 1.5 minutes. 15.27 1 starling on right roof. Feeds for 2 minutes. 15.40 1 magpie lands on right roof. Foraging for nest material. Leaves after 3 minutes with

leaves/grass in beak. OBSERVATION PERIOD 9 – Tuesday 6th April 2004 07.10 – 08.10 Sunny and cold • Right roof in sun, left roof in shade. After half an hour, both in sun. • Plenty of starling activity in area – mainly collecting and carrying nest material. 07.24 1 starling on right roof, soon followed by 3 more. 1 flies off with twigs and dead

leaves after 40 seconds, others stay and feed. 07.26 Magpie flies low over roofs and scares off starlings. 07.28 1 wood pigeon on right roof feeding (3 minutes). 07.30 1 starling lands on right roof, spends 20 seconds collecting dead leaves and flies off. 07.32 1 wood pigeon on right roof feeding. 07.33 1 starling on right roof collecting leaves for 10 seconds. 07.34 1 collared dove on left roof. Foraging briefly (10 seconds). 07.36 2 house sparrows on edge of right roof resting for 20 seconds. 07.37 1 wood pigeon returns to right roof and feeds. 07.38 Squirrel rests briefly on right roof before running across both roofs and into tree. 07.41 Second wood pigeon joins first on right roof. 07.48 1 wood pigeon leaves right roof (after 7 minutes), other stays. 07.54 1 starling right roof, soon 2. Both feeding. 07.55 Both starlings move to left roof where 2 others join them. Feeding for 30 seconds

before starlings and pigeon leave. 08.02 2 starlings land on right roof and collect leaves for 1.5 minutes.


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OBSERVATION PERIOD 10 – Wednesday 7th April 2004 17.00 – 18.00 Cloudy with sunny spells, light breeze 17.24 2 wood pigeons rest on edge of right roof. 1 for 10 seconds then leaves, other for 1

minute. Several pairs of blue tits flying around. 17.26 1 wood pigeon returns to edge of right roof. Roosts 30 seconds. 17.29 1 robin singing in tree to my left for 1 minute. 17.30 Pair of blackbirds now in tree. Blue tits feeding on cactus of tree further down

garden. 17.34 Pair of house sparrows land on edge of right roof. There for 40 seconds. 1 moves to

vegetated area briefly (10 seconds) to feed before both fly off. 17.40 1 magpie on right roof. Forages, rests on roof for 1.5 minutes but does not feed. 17.52 Flock of 8 starlings arrive in large tree to my right. OBSERVATION PERIOD 11 – Monday 12th April 2004 07.15 – 08.15 Sunny and cold • A lot of collared doves calling in surrounding trees throughout hour. 07.50 1 starling feeding at front edge of roof of house 6 for 10 seconds before moving out

of view. 07.55 Magpie rests briefly on back edge of right roof for 10 seconds. 07.59 Pair of starlings mate in tree to my right. 08.05 Magpie lands on right roof, then moves to left roof. Forages, pushing beak into

substrate for 30 seconds. OBSERVATION PERIOD 12 – Thursday 15th April 2004 17.50 – 18.50 Sunny, light breeze • Sun low in sky. Birds returning to trees. 18.15 Now a lot of noise from birds in area. 18.16 1 starling feeding at front edge of house 5. 18.18 1 starling on right roof feeding. Soon joined by 3 more. 18.19 1 wood pigeon lands on right roof and feeds (5 minutes). 18.20 All 4 starlings fly away. 18.21 2 starlings feed on grass of communal garden for 20 seconds, then fly onto right roof

and continue feeding. Joined by 1 more starling. 18.22 1 magpie lands on right roof and chases off the starlings. Stays for 2 minutes

feeding, chasing off any birds that come near. 18.34 2 starlings on roof of house 6. 1 perched on edge preening, 1 feeding nearby. Both

there for 1 minute then leave. 18.38 2 starlings fly by with nest material in beaks.


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13.4 Outline of study sent to Rolls-Royce Livingroofs.org Green roofs and biodiversity – small study of birds on extensive green roof Bird Study of the Rolls Royce Green Roofs, East Sussex The London Biodiversity Partnership and Royal Holloway College is undertaking a Green Roof and Biodiversity Study funded by the London Development Agency, Canary Wharf Management Limited, British Waterways and the People’s Trust for Endangered Species. Bird Study At present there is no information on how bird species are using green roofs in the UK. The only known study has been undertaken in Switzerland by Herr Stephan Brenneisen at the University of Applied Science Wadensvil. Herr Brenneisen is a partner in the above PhD. The green roofs at the Rolls Royce site near Chichester, East Sussex are the largest in the UK and therefore these roofs are likely to provide important data regarding how bird species use green roofs albeit in a rural setting. Helen Burgess as part of her degree at the University of Sussex has volunteered to undertake an initial bird study in the winter if access and agreement can be made with the relevant parties. Potential Benefits There is a growing interest in green roofs for biodiversity in the UK nature conservation sector. This small study and hopefully a more detailed study will provide valuable data that is likely to bring publicity to companies involved. The Laban Dance Centre in London, whose roof was designed specifically for biodiversity, has received wide-ranging publicity for its roof in national, regional and local press. In some cases such publicity has not been deemed in the interest of organisations and companies involved and therefore publication of data and press releases would be done only with the consent of relevant parties. Dusty Gedge Co supervisor PhD - Green roofs and Biodiversity Royal Holloway College c/o [email protected] November 2003


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13.5 E-mail from Matthew Frith (Peabody Trust) with list of UK green roofs From : Mathew Frith <[email protected]> Sent : 04 July 2003 09:57:10 To : 'Helen Burgess' <[email protected]> Subject : RE: Green Roofs

Attachment : chicagofinal150403.doc (129 KB), websitesandexamples.doc (38 KB)

Dear helen, Thanks for your e-mail. In short there are very few 'ecological' roofs installed in the uk, let alone london. In fact the only ones that have been installed with a specific ecological remit are those at the laban dance centre and creekside, both in deptford. The others, such as Shaw's Cottages in Forst Hill, have been installed for broader environmental benefits but with ecological benefits accruing from it. The english nature research I commissioned is now available on EN's website - but it's not easy to find. Go to the search engine and type in 'green roofs'. Its the dull dry reserach document rather than the more glossy that should have preceded it, but that will eventually come out [i hope]. The research report is due for 'official' launch next tuesday. EN also commissioned some research on invertebrates on green roofs in london, which has recently been published. contact Pete Massini [[email protected] or 020 7340 4870] for a copy. The attached is the paper I co-authored with James Farrell and presented at the recent green roofs conference in Chicago [Dusty and Stephan also presented, as you may have gathered]. I also attach the list of case study roofs featured in the English Nature report. <<chicago final 150403>> <<websites and examples>> I hope this helps... Regards, Mathew


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A selection of green roofs projects from the UK Project Designer/Builder Remarks Intensive Roofs BedZed, Beddington, London

Dunster 2001. Green development of dwellings/workspace. Solar panels. Roof gardens with 300mm soil. Also some extensive Sedum coir matting.

Birmingham Children’s Hospital

Lever/ Erisco Bauder Lawn

Bloomingdales Garden Centre, Laleham-on-Thames, Middx.

Cole Thompson/ Erisco Bauder

Lawn

British Gas Building, Reading, Berkshire

Foster/ Erisco Bauder Lawn

Castle Mall, Norwich, Norfolk Park on roof of car park. De La Warr Pavilion, Bexhill, East Sussex

Chermayeff/ Mendlessohn

1935. Simple intensive (lawn) on art deco pavilion

Derry and Toms, Kensington, London

George/ Hancock 1938. 6th floor roof garden. 600-1000mm2 of heavy silt loam soil. Slugs, snails, aphids, bees, wasps, butterflies. Plants leaf and flower 3 weeks ahead of those at ground level.

Earth Centre, Doncaster, Yorkshire

Niall Phillips/ Erisco Bauder

1999. Lawn

Ebley Mill, Stroud, Gloucestershire

Niall Phillips/ Erisco Bauder

Lawn

Gateway House, Basingstoke, Hampshire

Arup 197-1982. 2nd to 6th floor. Topsoil 225-900mm. Heavy planting. Irrigated. Pools. Nesting birds.

Harvey’s Store, Guildford, Surrey

1957. 6th floor. Roof garden with soil 75-100mm deep with 450mm deep planters for trees. Includes pools 100-300mm deep. Intensive.

Jacobs Island,London Scrivens/ ZinCo 1997. 6000m2 Roof gardens with pond over garages.

Kingston Hospital, Kingston upon Thames, London

1970.100mm - 800mm soil depth. Roof garden for staff.

Langdon Cliffs, Dover, Kent Van Heningen & Hayward/ Niall Phillips/ Erisco Bauder

Lawn

Longmans, Harlow, Essex C D Partnership Roof garden with low shrubs National Theatre, London Euroroof/ ZinCo 1996. Intensive planted beds on terrace. Plantation House, City of London

Arup/ Erisco Bauder Shrubs and perennial borders

RMC HQ, Runnymede, Berkshire

Cullinan/ Lovejoy 1990. 4500m2 simple intensive roof garden.

Royal Northern College of Music, Manchester

1974. 2nd floor courtyard roof garden, irrigated.

Sainsbury Centre, Phase 2, UEA, Norwich, Norfolk

Foster Lawn

Sir Joseph Banks Centre, RBG Kew, London

Broadway Malyan 1986. LECA substrate, irrigated.

Wesleyan Assurance, Birmingham

Hing and Jones/ Erisco Bauder

Low flowering shrubs in roof garden

West Suffolk Hospital, Bury St.Edmonds, Suffolk

- 1978. 100mm compost on sloping 1st. floor roof secured by netlon. Irrigated.

Willis, Faber & Dumas, Ipswich, Suffolk

Foster 1971. Irrigated lawn on 225mm of loam.


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Extensive Roofs Almeida, Kings Cross, London

Clarke/Erisco Bauder Sedum blankets on steeply pitched roofs.

Birchdene Drive, Thamesmead, London

Architype 12 houses, turf

Bix Barn, near Henley, Oxon Simmonds Mills 1993. Chalk turf on barn at BBOWT Warburg Nature Reserve

Bix Hide, near Henley, Oxon Simmonds Mills 1992. Turf on bird watching hide at BBOWT Warburg Nature Reserve

Calthorpe Project, Kings Cross, London

Architype Turf

Cambridge University Sports Centre, Cambridge

Arup 10,000m2 of earthsheltering

Canary Wharf, London Gibbons Sedum Canoe Lake Toilets, Portsmouth, Hampshire

Erisco Bauder Sedum

Castell Henlys Iron Age Centre, Pembrokeshire

Niall Phillips Turf

Centre for Alternative Technology (CAT), Powys

Various Turf roofs on several exhibition buildings

Centre for Understanding the Environment, Horniman Museum. Forest Hill, London

Architype Turf

Chisholm House, Ditchling, East Sussex

Jon Broome Turf

Crowe Hall, Bath, Avon Hadfield Associates/ Erisco Bauder

Sedum

Cumbria Visitor Centre, Penrith, Cumbria

Quarmby 1990. Extensive roof

Diggers, Brighton, East Sussex

Architype/ EcoSchemes

1994. 10 houses, self-build scheme. Turf roofs. DOE/RIBA/NHBC Housing Design Award for 1997.

Dobbs Cross, Saddleworth Moor, Yorkshire

Corus 2000. Kalzip Nature Roof (Sedum). Trial site on stable block.

Earth Centre Doncaster, Conference and Arrivals Centre, Yorskhire

Dunster/ Erisco Bauder

Sedum

EcoTech Building, Swaffham, Norfolk

Alumsac Sedum

Environment Agency Offices, Bodmin, Cornwall

Form Design Group/ Erisco-Bauder

Sedum

Findhorn Village, Scotland Talbott 1991. Turf on second round of eco-homes and youth centre.

Garden Retreat, Cadmore End, Buckinghamshire

Neil May/Simmonds Mills

1995. Turf stabilised by split chestnut and rope ‘ladders’ laid over chalk rubble.

Great Notley Primary School, Essex

AHMM/ Erisco Bauder Sedum

Hedgehog, Brighton , East Sussex

Architype/ EcoSchemes

10 houses, self build scheme, turf.

Hooke Park, Dorset Simmonds Gough Mills

Turf on bark mulch on butyl membrane, student project (now demolished)

House for the Future, Museum of Welsh Life, Cardiff

Jestico & Whiles/ Corus

2000. Kalzip Nature Roof (Sedum)

Ilfracombe Pavilion, Ilfracombe, Devon

Ronalds/ Erisco Bauder

Extensive roof

Integer House, BRE, Cole Thompson/ 35 degrees pre-cultivated 'Xeroflor' XF300


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Watford, Hertfordshire

Erisco Bauder vegetation blanket with a hydroscopic mineral wool mat rootzone

Interpretation Centre, Wessex Water, Weston-super-Mare, Somerset

Erisco Bauder Large Sedum roof

Laban Dance Centre, Deptford Creek, London

Creekside Environment Project

Brownfield roof – first of several planned for the Deptford Creek area

Little House, Laindon, Essex Jon Broome Turf London Wildlife Garden Centre, Peckham, London

Architype / EcoSchemes

1990. Turf. Extensive. Times/RIBA award for community architecture.

Liss Junior School, Hants HCC architects/ Erisco Bauder

Sedum

Making Place, North Kensington, London

Architype Turf

Matzdorf House, Islington, London

Jon Broome Turf

Millenium Seed Bank, Wakehurst (RBG Kew), East Sussex

Alumasc Sedum

Moorside Road, Lewisham , London

Architype 14 houses, turf

National Federation of City Farms, Bristol

Architype Turf

National Wildflower Centre, Court Hey Park, Liverpool

Hodder Seeds sown into recycled textile matting under gravel

Nottingham University Campus, Nottingham

Hopkins/ Erisco Bauder

Sedum

Opera House Extension, Winchester, Hampshire

Corus 2002. Kalzip Nature Roof

Paignton Zoo, Paignton, Devon

Elliot Sedum

Pizza Hut/ Asda , Swindon, Wiltshire

Corus 2002. 485 m2 Sedum species on Kalzip Nature Roof

Pizza Restaurant, Jersey Riva/ MEPK/ Corus 2000. Kalzip Nature Roof (Sedum) Raleigh Gardens, London Penoyre and Prasad/

Erisco Bauder Sedum

St David’s Information Centre, Pembrokeshire

Smith Robert/ Erisco Bauder

Extensive grass

St Paul’s Bus Station Walsall Allford, Hall, Monaghan, Morris

Turf on concrete shell

Scottish Widows, Edinburgh Sylvia Crowe 1976. Roof of multi-storey car park 100-500mm of silt loam with peat planted with low shrubs/heather.

Shaw’s Cottages, Forest Hill, London

Jon Broome/ EcoSchemes

1993. Turf roof on a new house in Lewisham. (see case study)

Skirmet Shed, Bucks Simmonds Mills 1994. 25m2 100mm thick turf roof Surrey Docks City Farm, Rotherhithe, London

Architype Turf

Sutton Courtenay Environmental Education Centre, Didcot, Oxon

Simmonds Mills 2002. Plants from site planted into nutrient poor soil over geotextiles.

Underhill, Yorkshire Quarmby Part lawn, part extensive grass, part shrubs and heathers

Westonbirt Arboretum, Gloucestershire.

Simmonds Mills 1994. Turf on 80m2 roof of shelter.


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13.6 Letter to Diggers residents

17th February 2004 Dear Sir/Madam, As part of my final geography degree project I am studying green roofs, in particular the bird life that they help support. Although this is a purely observational study, it is the first of its kind undertaken in the UK. Diggers is a very successful example and over the coming weeks I plan to record the bird activity for an hour at a time, twice a week. My proposed timetable, starting on Monday 23rd February, is as follows: 7-8am on Mondays 2-3pm on Wednesdays My contact so far has been with Rosie at Number 9 and it is near here I plan to sit and watch the birds on the roofs of houses 1-4, so if you see me you will know what I am up to. I do hope that this is OK with you and that you do not feel that this is any sort of intrusion. If you have any problems or questions, my number is 07743 320783. Thanks! Helen Burgess

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