At seven storeys, construction firm

CCG (Scotland)'s recently

completed Ellerslie Road

development is Scotland’s tallest

timber building. It is also Scotland's first

multi-storey domestic CLT (cross-laminated

timber) building. Building Warrant approval

has set a precedent in the country, the

result of evidence supplied to Building

Standards Scotland, Glasgow City Council

and Scottish Fire & Rescue Services.

Built on the banks of the River Clyde at

Yoker, a town just west of Glasgow,

Ellerslie Road provides 42 one-, two- and

three-bedroom contemporary mid-market

rent apartments for Sanctuary Homes, part

of Sanctuary Group. The new building,

which was designed by MAST Architects,

optimises the efficiency of CLT with six

apartment modules arranged around one

central stairway in a ‘T’ shaped form.

Apartments are designed around a

standard template used by CCG for all

residential units, however CLT’s ability to

achieve long, uninterrupted spans has

allowed for a flexibility in the layout of

apartments from floor to floor which would

have been more constrained with

traditional forms of construction. Engineer

Smith and Wallwork was responsible for

the design of the cross-laminated timber

superstructure, working collaboratively

with solid wood specialist Eurban at detail

design stage to ensure a smooth offsite

manufacture and onsite assembly process.

The entire superstructure is built from

Stora Enso PEFC certified CLT including

the common areas and lift shaft.

Structural wallsThe lift shaft structural walls are formed by

100mm thick CLT panels tied together to

form a rigid tube with the shaft independent

from the CLT separation wall between lobby

and apartment. The CLT shaft is restrained

laterally at each of the seven floor levels

with the CLT panels forming the lobby slab

and capped with a 120mm thick CLT 'lid'

used to fix the hooks to install the lift without

the need for any steel lifting beam.

A bespoke platform is used to support

the superstructure due to the

lightweight nature of CLT and the

exposure to wind loadings along the

HOUSING & REGENERATION

river. The superstructure includes

design features to provide enhanced

resistance to disproportionate collapse

and this has encouraged the Institution

of Structural Engineers ( IStructE) to

start a review process for Part A3 –

Building Regulation Disproportionate

Collapse as it is recognised that there

are a number of forms of construction

that would benefit from a review.

Rigorous standards“This is the first major domestic CLT

building in Scotland and Scottish Building

Regulations are vigorous, requiring a

supervising engineer to sign off all

calculations prior to construction,”

comments, Simon Smith, Director at Smith

and Wallwork. “One of the key issues

when building with CLT is efficiency, in

terms of material use and standardisation.

“At Yoker we have managed to deliver

a standard CLT platform construction

using standard connection details and no

platform reinforcement. CLT use density is

0.29m3/m2, which is low considering the

tall and exposed nature of the site.

Earlier this year Sanctuary Homes completed the first major domestic cross-laminated timber(CLT) building in Scotland at Ellierslie Road in Yoker, near Glasgow. LABM has all the details.

© CCG (Scotland) Ltd. The CLT panels being installed

Stand tall

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“ The superstructure includes design features to provide

enhanced resistance to disproportionate collapse and

this has encouraged the Institution of Structural Engineers

to start a review process for Part A3 – Building Regulation

Disproportionate Collapse.”

© CCG (Scotland) Ltd. The project is the subject

of two academic research programmes

© CCG (Scotland) Ltd. The apartment block was

built on the banks of the River Clyde at Yoker

The lightweight nature of the CLT

structure reduces foundation loads but

does mean the exposed River Clyde site

causes some challenges due to wind

loadings and ultimately with holding down

the building; in several instances we have

tied the CLT down to the concrete

foundations which act as ballast.

“We also had some interesting

discussions with the gas industry and their

representatives about disproportionate

collapse.” Simon continues: “In Scotland

gas is often delivered to the door of

individual dwellings which is therefore

considered as a higher risk on an

apartment by apartment basis. We were

able to present robust evidence to the

Institution of Gas Engineers & Managers

(IGEM) that CLT structures can provide an

enhanced resistance to disproportionate

collapse and that Yoker in particular has

some enhanced disproportionate

collapse design features in terms of

notional removal.”

Matthew Linegar, Head of Building

Systems at Stora Enso and a Structural

Engineer who has spent 12 years

specialising internationally in CLT

construction comments: “The way in which

CLT elements are connected together

with many small ductile fixings and the

lighter weight nature of the material allows

panels to effectively re-distribute tensile

forces which may occur during a collapse.

“Until there is codified guidance for

disproportionate collapse, it is important

when using CLT for multi-storey

residential buildings to engage with

authorities and stakeholders early in the

design stage to allow designers to

respond and to accommodate the roof

Project fact file: Ellerslie Road,

Yoker, Glasgow

• Completed: January 2018

• Client: Sanctuary Homes

• Main Contractor: CCG (Scotland)

• Architect: MAST

• Timber Engineer: Smith and

Wallwork

• Structural Engineer: Scott Bennet

Associates

• CLT Installer: Eurban

• CLT Manufacturer: Stora Enso

requirements effectively in the creation of

safe and cost competitive buildings.”

Advantages of CLT

Ellerslie Road used 1,240 m3 of CLT, which

equates to a total of 757 tonnes of CO2

being removed from the earth's

atmosphere. Other key benefits of building

with CLT include the material's inherent air

tightness and thermal properties, which

mean that residents will benefit from

energy savings when compared to

traditional methods of construction. Solar

PV panels have also been installed on the

roof providing long-term energy savings

on residents’ energy bills. Building with

cross-laminated timber also resulted in

reduced construction time, thus minimising

impact on the surrounding community with

the entire seven-storey superstructure

installed and wind and watertight in a net

period of 16 weeks.

The project is the subject of two

academic research programmes looking

at factors including CLT’s airtightness,

acoustics, thermal performance,

productivity, LCA/whole life costing and

the building’s interaction with wind.

With thanks to Stora Enso for

preparing this article

n www.storaenso.com

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