Sustainable Design

Buildings designed and built according to sustainable design principles can save energy, water and money while being comfortable to occupy. The City of South Perth is committed to sustainable practices that enhance the quality of life of the community.

The objectives of sustainability are to reduce consumption of non-renewable resources, minimise waste and create healthy, productive environments. Houses designed and built according to sustainable design principles can save energy, water and money while being naturally comfortable to occupy.

The City strongly encourages the use of design solutions that will optimise solar access, maximise energy efficiency and conserve water.

Passive solar design

Wherever practical, the site planning and design of dwellings should employ basic passive design principles:

Orientation of the dwelling maximising north facing walls and glazing
Siting homes for solar access, exposure to cooling breezes and protection from cold winds
Minimising all east and west facing glazing and using adjustable shading techniques and strategic planting of shade trees
Eaves to provide protection against summer sun
Cross ventilation opportunities
Use of bulk insulation of walls, ceilings and exposed floors to keep heat in during winter, and reflective insulation to keep heat out during summer
Correct use of thermal mass
Use of convective ventilation and heat circulation
Use of entry airlocks and sealing to reduce draughts.

Insulation, roof colour and thermal mass

Roof-space insulation is a great way to improve your house’s energy efficiency and is also a Building Code of Australia (BCA) requirement for all new houses. Consider insulating other parts of your house as well, such as walls. When selecting insulation, compare the ‘R’ values, which are a measure of resistance to heat transfer. Generally the higher the ‘R’ value, the greater the resistance.

In addition, choosing light coloured materials for roofs and walls can help reduce the amount of heat absorbed. Light coloured materials reflect the sun’s energy and stay cooler than dark coloured materials.

Thermal mass is the ability of a material to absorb and store heat energy. A lot of heat energy is required to change the temperature of high-density materials like concrete, bricks and tiles – these have high thermal mass. Lightweight materials such as timber have low thermal mass. Appropriate use of thermal mass throughout your home can make a big difference to comfort and heating and cooling bills. As concrete and tiles store heat longer than timber floors, they are very useful for absorbing and storing heat from winter sun.

Sealing

External doors should be sealed to keep cool air in during summer and out during winter. Window frames should also be well sealed to minimise heat loss in winter and heat gain in summer.

Materials selection

Careful selection of environmentally friendly materials for construction can significantly improve the health, comfort, cost effectiveness and energy efficiency of your home. The following guiding principles should be considered:

Where possible, use recycled materials or materials with recycled content
Understand how chemicals used in the manufacture of some materials might affect your health
Consider how and where the materials are sourced and the impacts of this
Design and build for de-construction, re-use, adaptation, modification and recycling
Ese durable and long lasting materials.

Solar power

Solar power systems use solar photovoltaic panels on the roofs of buildings to capture the sun’s energy to generate electricity and/or hot water.

Appliances

Enhance the sustainability of your house by using energy efficient appliances. All new homes must use taps and showerheads with a minimum WELS (Water Efficiency Labelling Standards Act 2005) rating of three stars. Toilets must have dual flush and a minimum rating of four stars.

Gas-boosted solar hot water systems or heat pump systems can save hundreds of dollars on energy bills annually, compared to standard electric systems.

Water-sensitive design

There is a growing awareness of the importance of water to our survival and its limited supply in a place as dry as Western Australia. Cutting back our fresh water use can significantly reduce household water bills and demands on public water supply.

Consider the following in the design of your home and garden:

Landscaping designed for low water use
Installation of rainwater tanks
Use of ‘grey water’ where appropriate.

Collected rainwater can be used for toilets, laundries, pools, gardens and even for drinking if treated correctly.

Wastewater from non-toilet fixtures such as showers, basins and taps is known as grey water. With proper treatment, grey water can be used for laundries, toilet flushing and irrigation of plants and lawns. The nutrients found in grey water, including phosphorus and nitrogen, can be an excellent food source for a wide range of plants.

Kitchen wastewater contains fat, oil and food residues that pose a potential health and environmental risk. The Western Australian Department of Health provides a list of suitable grey water reuse systems approved for domestic use. If you wish to install a grey water recycling system, you must first submit an Application to construct or install an aparatus for the treatment of greywater to the City of South Perth Environmental Health Department for assessment, in compliance with council and state government requirements.