Sustainable House Day, Christie Walk 5, Adelaide, SA

New or retro: New. The house was built in 2003.

Climate Zone: Mediterranean

Architect: Paul Downton

Unique Sustainable Elements featured in this home

Water harvesting
- Underground rainwater storage
Water for flushing the toilet in this house comes from a common stormwater source which is collected into two 20,000 litre undergound tanks which are topped up automatically from the mains supply in dry weather. This water is also supplied to all garden areas in Christie Walk. Average water usage from the mains, per household, is 69 kl per annum.
HDPE fittings are used in this building and some of the surrounding area.

External walls
- Low embodied energy
- Sustainable sources
- Timber choice: Recycled
- Low toxicity
- Long life
- Adaptive reuse
Recycled timber framing with 500mm straw bale infill and plastered finish.

Internal walls
- Low embodied energy
- Sustainable sources
- Timber choice: Recycled
- Low toxicity
- Insulation: R3 recycled polyester
Internal walls are timber with plasterboard finished with low toxicity paint and varnish and insulated with polyester batts.

Roof
- Insulation type and rating: Polyester batts R3
- Colour choice: Light for reflection
- Pitch: to suit solar collection
- Curved roof line
The ceilings are insulated with polyester batts containing recycled PET bottle plastic. It is non-toxi and non-itchy to handle

Floor
- Thermal mass
- Long life
Timber floor is recycled and coated with low toxicity varnish.

Window treatments
Windows are double glazed and varied in size with small several low hung windows to allow summer breezes into the home.

Electricity generation
Mains electricity used but annual bills are less than $450 for two people.

Heating & Cooling
- Passive cooling
Summer cooling relies on outside window shading,  cross ventilation, thermal flue effect of spiral staircase and roof window opening, and louvre windows between some rooms. There are also internal curtains and blinds and ceiling fans in every room.
In the winter we use  electric heaters but the well insulated walls and double glazed windows reduce heat loss.

Water Heating
Solar water heating used from October to mid April. As our house is overshadowed by a neighbouring building, in the winter we use the electric back-up but leave it turned off until we need to heat the water. It takes only half to ¾ hour to heat enough water for daily use

Appliances
Stove and fridge selected for high energy efficiency. Shower head is low flow.

Other
At Christie Walk there are many other features of sustainable urban living outside of the houses. We have vegetable and fruit gardens, a rooftop garden on one of the apartment blocks, a shared laundry and a shared community room for leisure activities and meetings. Recycling is a priority – using kitchen waste for composting, donating unwanted items to others etc. There is a bike shed for 20 bikes, people use public transport and several residents have joined the GoGet carshare scheme enabling them to sell their cars and just pay for car use as needed.