Building a home using good passive design principles which can save energy, water and money is fundamentally about understanding and responding to the climatic.

The Tweed is located within a sub-tropical climate zone where the main characteristics include:• Highly humid with a degree of dry season;• High temperatures year round with mild winters;• Minimal seasonal temperature variation; and• The lowest diurnal (day/night) temperature range.• Higher than average rainfall.

If you are building, buying or renovating, there are a number of simple measures you can implement to create a more comfortable home that has less impact on the environment, more economical to run, healthier to live in and adaptable to your changing needs.

With the Tweed’s temperate sub-tropical climate, well designed houses should only require a limited amount of heating and cooling. During the preliminary design stage of your house consider the following:

` The north side is warmer in winter and the best place for rooms you use a lot, like living areas, outdoor rooms and decks.

` The west side gets hot in the afternoon and is best for rooms you don’t use often, like bathrooms, garages and laundries.

` The south side is the coolest zone and good for bedrooms, as well as rooms you don’t use often, but can also a good place to seek refuge from the sun during summer months.

` The east side gets morning sun and is good for breakfast rooms, kitchens and bedrooms

It is equally important to design for cross ventilation to flush out the heat generated during the day. The heat load from unshaded sunlight into buildings during the hotter months can be a problem. Click on http://www.tweed.nsw.gov.au/PlanDevBuild/SmartHousing.aspx for 10 considerations for smarter more energy efficient housing.

Designing to suit Tweed’s climate Your guide to building a house

Tweed Shire Council

In summer - protect your home from heat gain from low angle sunlight on the eastern and western walls by designing deep eaves, vertical shading, screens or blinds and integrating landscape and shade trees. Ensure good ventilation to mitigate the effects of thermal mass during summer months.

In winter - solar access should be maximised to improve heat gain from the lower northerly sun path. Floors and walls made of higher mass (brick, concrete, tiles) material will store heat during the day which will be released at night to warm the house.

Thermal mass and shading

Spring / Autumn

Win

ter

N

S E

WSum

mer

COOL SUMMER BREEZES

SOUTHERLY BUSTER DRIVEN WIND AND RAIN

HOT SUMMER SUN

N

S E

W

WINTER SUMMER

Building Shape and Orientation - Narrow spaces promote better air circulation. Design spaces and window placements that will pick up prevailing breezes and promote cross ventilation.

Ventilation - Higher level windows or ceiling cavity will create stack ventilation which allows hot air to continually escape and be replaced by cooler air.

Cross ventilation

Spring / Autumn

Win

ter

N

S E

WSum

mer

COOL SUMMER BREEZES

SOUTHERLY BUSTER DRIVEN WIND AND RAIN

HOT SUMMER SUN

N

S E

W

WINTER SUMMER

Spring / Autumn

Win

ter

N

S E

WSum

mer

COOL SUMMER BREEZES

SOUTHERLY BUSTER DRIVEN WIND AND RAIN

HOT SUMMER SUN

N

S E

W

WINTER SUMMER

Climate and orientation

Solar Access and Orientation - A northern orientation for living areas and outdoor spaces is generally the best for the Tweed’s climatic zone. From sunrise to 9am and from 3pm to sunset the sun is lower in the sky. House design should acknowledge and shade potential high heat loads from the south east during summer mornings and south west during summer afternoons.

Insulation - Wall, floor and roof insulation enables a more stable internal temperature both during the summer (keeping heat out) and winter (keeping heat in).

Spring / Autumn

Win

ter

N

S E

WSum

mer

COOL SUMMER BREEZES

SOUTHERLY BUSTER DRIVEN WIND AND RAIN

HOT SUMMER SUN

N

S E

W

WINTER SUMMER

Spring / Autumn

Win

ter

N

S E

WSum

mer

COOL SUMMER BREEZES

SOUTHERLY BUSTER DRIVEN WIND AND RAIN

HOT SUMMER SUN

N

S E

W

WINTER SUMMER

Insulation

Source: Smart & Sustainable Homes’ Designing for Queenslands Climate’

Sustainable design - Designing for cross ventilation, solar aspect, sunlight shading and water collection forms the foundation of a good sustainable house design.

Source: Sparks Architects

Design for climate - Designs which successfully integrate indoor and outdoor living spaces and include well considered landscape and garden areas with shade trees are ideal for the subtropical climate.

Source: Peter Stutchbury Architects

To respond to Tweed’s subtropical climate try and incorporate the following passive design features:

Site design principles• Plan to optimise solar aspect on the site, generally with living spaces

oriented north, sleeping to the south or east and utilities (garages, bathrooms and laundries) to the west.

• Elevated housing, spaced apart with strategically placed windows and openings to capture cooling summer breezes.

• Retain (or plant) vegetation, in particular trees, for shade.

Floor plan and building principles• Design with living spaces to the north east, north or north west as

the best solar aspects. All west and east facing walls and windows should be shaded year round.

• Design narrower floor plates to assist with cross ventilation, alternatively design openings to receive prevailing breezes.

• Design higher volumes with higher level operable windows in living spaces to assist with stack and cross ventilation.

• Try and reduce the house profile and windows facing west. If you have a long western elevation extensively shade with deep eaves, window hoods or a covered verandah to act as a buffer to hot summer sun.

• Maximise the indoor and outdoor relationship with screened and shaded areas and rain protected outdoor areas, such as large and covered verandahs accessed directly off living spaces.

• Consider multiple outdoor living areas or decks to take advantage of the sunny side (for winter) and the shady side (for summer) of the house, and a morning deck and afternoon deck.

• Incorporate ceiling fans for air movement.

Materials• Generally use insulated lightweight building materials with plenty

of opening windows enabling quick release to heat during summer months, but retention of internal heat source during winter months.

• Generally use low thermal mass construction due to the low diurnal range. Where incorporating an element of thermal mass (brick, concrete, masonry), ensure that space is appropriately ventilated during summer months to quickly release the stored heat.

• Use light coloured walls and roofs to reflect more solar radiation and reduce heat gain.

• Minimise solid masonry fencing, colourbond fences and high retaining walls which blocks cooling breezes to the ground floor and yard spaces compared to landscape and ‘neighbour friendly fences.

• Incorporate insulation to ceilings and walls and underside of suspended floors.

Building elements and appliances• Collect your rainwater and reuse it through your toilets, washing

machine, dishwasher and to water your garden.• Energy efficient hot water systems such as solar hot water, natural

gas and electric heat-pumps will lower your water heating bill and reduce the households carbon footprint by an average of 4 tonnes of CO2 per year.

• Install water saving shower heads and toilets with a 3 stars rating or greater.

• Install appliances with good energy ratings.• Consider solar panels for generating electricity.• The most energy efficient light is natural light. Where artificial

lighting is required match the lighting type with particular lighting needs and energy efficiency ratings.

N

S

30

300

330

240

210 150

0618

15

15

15

09

09

09

12

12

12

10°

20°

30°

40°

50°

60°

70°

80°

90°

120

60

W E

SUM

MER SOLAR PATH

Summer sun rise 04:46Summer sun set 18:42

Equinox sun rise 05:50

Winter sun rise 06:37

Equinox sun set 17:57

Winter sun set 16:59

EQUINOX SOLAR PATH

WINTER SOLAR PATH

North eastern is the cooling breeze during summer months in coastal areas.

East to south east strong winds and weather changes predominantly during winter months particularly along coastal areas.

Warming afternoon sun during winter months.

Hot western and south western sun during summer months.

Tweed Solar Path Diagram - Solar path and prevalent climatic influences for the Tweed.

Tweed Shire Council

Sub-tropical design elements and principles