Source: www.sustainable-homes.org.au
Ecologically sustainable development (or sustainability) is defined as development that improves the total quality of life, both now and in the future, in a way that maintains the ecological processes on which life depends. The five key principles from the Foundation of Sustainability are:
• Integration—the effective integration of environmental, social and economic considerations in decision making.
• Community involvement—recognition that sustainability cannot be achieved, nor significant progress made toward it, without the support and involvement of the whole community.
• Precautionary behaviour—where there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.
• Equity within and between generations—fairness and equal access to opportunities both in our lifetimes as well as for future generations.
• Continual improvement—the declining environmental situation means there is an imperative to take immediate action to become more sustainable and to make continual improvement.
Sustainability is a very broad, all encompassing concept that has implications for every aspect of society, including people of all ages and abilities. However, the concept does not need to be difficult to resolve if the triple bottom line approach is considered and applied.
Homes that incorporate sustainable design features will derive numerous ongoing benefits, including enhanced value.
The triple bottom line approach towards sustainability
1. Environmental Sustainability
Environmentally sustainable homes minimise the impact on the environment by incorporating features such as rainwater tanks, energy efficient hot water systems and passive solar design for the local climate. The design of a home for environmental sustainability needs to address, but is not limited to, the following:
Energy:
The design of the home maximises the use of natural energy and minimises the need for non-renewable energy. The home includes passive solar design features such as house orientation, ventilation, insulation and shading, appropriate use of building materials and fixtures and fittings, to ensure higher energy efficiency and help the environment by reducing household carbon emissions. The home has energy efficient appliances.
Water:
The design of the home and outdoor areas, including its fixtures, fittings and appliances, saves water.
Materials and waste:
The design and construction of the home considers the efficient use of building materials, minimises waste and uses recycled materials where possible. Construction aims to minimise environmental impact, e.g. run-off to waterways. It takes future needs into consideration so that it minimises the requirement for modifications and consequent material wastage.
Site impact and biodiversity:
The site of the home and the landscaping considers the natural features of the site, including topography, the local climate, native flora and fauna, and natural and cultural features. Design considers retaining existing vegetation, including trees. The landscaping requires minimum maintenance and water, inhibits soil erosion and minimises storm water contamination and damage.
2. Social sustainability
Socially sustainable homes are designed with all people in mind. Features such as flexibility, comfort, access, safety and security are addressed so that homes accommodate the changing needs of occupants and guests. The design of a home for social sustainability needs to address, but is not limited to, the following:
Human comfort:
The home provides an internal environment that is thermally, visually and acoustically comfortable.
Human health:
A healthy home reduces hazards to human health within the home (e.g. the presence of toxic chemicals, mould, etc) and promotes natural lighting and ventilation.
Safety:
The design minimises the possibility of falls, driveway run-overs, burns and poisoning and enhances the ability to supervise children in outdoor play areas. The likelihood of injuries occurring in and around the home for people of all ages is reduced.
Security:
The home uses designs, fixtures and fittings to reduce crime and protect the home from malicious intruders. It enables informal surveillance of the yard, street, and neighbouring properties.
Universal design:
The home is versatile and comfortable for a diverse range of people and at different stages of their lives. It is easy to move around the home, and the operation of fittings and fixtures caters for people of all ages and abilities. The home is easily accessed by occupants, visitors and emergency services, etc.
Sense of community:
The home contributes to an improved community identity by enhancing the urban fabric of the neighbourhood and promoting opportunities for neighbourhood interaction through appropriate design.
3. Economic Sustainability
Economically sustainable homes are more cost-efficient over time. They feature smart design and use low-maintenance materials and appliances with high water and energy-star ratings to reduce the ongoing costs of running the home. Natural heating and cooling can be achieved by considering orientation, ventilation, insulation, shading and materials. The design of a home for economic sustainability needs to address, but is not limited to:
Initial costs:
The design of the home considers the size of the dwelling to reduce the cost of construction. The costs of building materials are calculated on their capital costs as well as their potential ongoing savings and cost effectiveness. The design considers standard sized products and the use of recycled, readily available and local building materials.
Maintenance costs:
Selection of building materials considers the long-term maintenance expenses. The design includes durable and low maintenance materials.
Running costs:
The home utilises alternative energy sources (e.g. solar and gas) and uses energy and water efficient appliances. Effective passive design reduces the need for artificial lighting and climate control.
Future modification costs:
The design minimises the need for future modifications to cater for the occupants’ changing requirements, which reduces long term costs.
Community costs:
The design of the home works to minimise the costs to the broader community, for example, utility and transport costs, provision of medical and emergency services, as well as fitting in with the context of the neighbourhood.