Question 1. What is a sustainable home?

Sustainable home design is really just common sense

A sustainable home is a home built on common sense house. Simply put it is a home that makes effective use of the site, the natural resources available and the lay of the land to produce a home that minimises construction costs, maximises livability and has low or no operating costs. A sustainable home:

  • has, as far as practicable, low embodied energy (energy expended in the manufacture of the building products)
  • uses the building materials and mass of the earth to provide a thermal bank to maintain a relatively constant temperature. This eliminates, or minimises, heating in winter and cooling in summer.
  • limits the use of natural resources; ie, efficient use of electricity, wind and water.   
  • uses the wind to channel prevailing breezes to cool in summer.

The principles that must be considered when developing a sustainable home are:

Passive design

A passively designed home makes the most of natural heating and cooling methods to keep its occupants comfortable year-round. Orientation, spatial zoning, thermal mass, ventilation, insulation, shading and glazing are the seven core components of passive design, explains sustainable designer Dick Clarke of Envirotecture.

Home orientation is particularly important in the  cool climate zones of the Yass Valley. It is important for the building to be correctly oriented to the sun in during cold seasons and shut it out when it’s hot, the other six principles of passive design can be balanced to create homes that require minimal active heating or cooling. Good orientation from a passive design perspective generally means locating living areas on the north side of the house, with glazing having clear access to sunlight even in mid-winter.

Design for climate

Different climates need different houses and Australia has more than 80 climate zones . The design and delivery of homes that are appropriate to the climate and adapted to both your needs and the micro-climate of your site. Design is more than just the structural components of the building - but the balance of light, heat and insulation to achieve the best balance of utility and cost - both construction and running. 

Heating and cooling

Traditional Australian construction standards result in ‘leaky’ homes; the air changing up to twenty times in an hour. This leakage creates draughts and results in increased heating and cooling costs, Sealing leaks post construction is difficult and costly. The key design factors are: prevent leaks, use curtains and blinds to manage heating and cooling and insulate. Ceiling fans should be considered for both heating and cooling to increase efficiency.


Insulation provides a barrier to heat passing in and out of the house, In many cases good design and good insulation can a provide a dwelling that requires limited, or no, heating or cooling. le temperature inside, regardless of the temperature outside. In winter, once your home has been heated to a comfortable level, it will stay that way with less energy input than an uninsulated home. Insulation and the exclusion of draughts can result in a saving of up to 30% in energy bills.


Windows and glazed doors can leak considerable heat (in and out). Good design will determine the optimum glazing requirement; consider the benefits of double glazing but there is no need to go overboard chasing energy rating stars. Balance the cost of the windows with the projected savings over time in relation to heating and cooling to find the right balance,

Size matters

We here in Australia have some of the biggest houses in the world; this is not particularly efficient. Good design maximises the utility of the home and results in higher energy efficiency standards, and lower upfront and ongoing costs.

Design for duration

Make sure your home is designed for the long haul; ie, durability in terms of material and utility. Consider the following: will the family grow, will it shrink or will it stay stable. If this is your forever home design a home that not only meets your current needs but can adapt.

Design for operating costs

It is important when considering operating costs to consider the relationship between designing for climate and the impact this has on energy consumption, After heating and cooling lighting and refrigeration are the next biggest consumers of energy. Consider providing a vent behind the fridge and freezer to allow heat to be extracted using natural convection, reducing operating costs. Use energy efficient lighting and appliances to further reduce the ongoing costs. The premium for energy efficient appliances is not much if you shop around. In most cases the up front cost will be more than offset by reduced running costs over time.

During the design phase consider the addition of renewable power - a well designed house can be energy neutral if integration is done well. Considering where the energy market is heading an informed decision during design is likely to provide profound dividends in the future.

Design for water

Use three or four WELS star-rated shower heads, toilets and water fixtures. Catch your rainwater in tanks for use in the bathroom and garden and, depending on your location, consider wastewater treatment. Use drought tolerant landscaping.

Use of sustainable materials

Generally, the more processed a material is, the higher its embodied energy. So choose sustainably sourced timbers, recycled and locally sourced materials, and low volatile organic compounds (VOC) paints and finishes. When building, keep material use to a minimum. If you’re renovating, reuse what you can from the pre-existing building.

Manage the inside environment

Work with the elements to maintain your home in a comfortable state at all times. This not only reduces ongoing costs but provides that liveable feeling; use curtains and blinds to manage light and heat, windows to provide (or prevent) cooling breezes through cross ventilation of convection, thermal mass and renewable energy to cool or warm the home using free energy and then maintain it during the peak hours, In short manage the inside environment to make the most of your passive solar design.