What does a completely sustainable house look like?

Learn how old-school design features alongside solar power can make your house completely sustainable and more energy efficient.

When designing our four-bedroom, off-grid solar home on a small acreage west of Melbourne, my family and I found there were plenty of sustainability lessons to be learnt from local historical architecture. We found Melbourne-based sustainable design architect Sarah Rickard of Positive Footprints Architects helped out with our queries.

“Early Australian architectural design was all about passive heating and cooling, which is why heritage properties remain popular today,” says Sarah.

“The fantastic thing is that those ‘old-school’ design features can be applied to any building style from traditional homestead to modern minimalist.”

So, if you’re planning an energy-efficient home, pairing some of these design features with an efficient photovoltaic (PV) solar system – which basically means the system converts sunlight directly into electricity – is one of the best ways to increase your energy star rating and green up your home’s credentials.

There are four ideas my husband and I found helped passively heat and cool our home, keeping it as sustainable as possible, while perfectly complementing our solar system:

1. House positioning.

Spend some time on your block to see where prevailing winds, light and shadows come from.  By facing your living areas north, you’ll passively warm those high-use areas.  Allow adequate roof space in your house plans on which to install solar panels. We mounted ours on the garage roof, ensuring it was clear of large trees and north facing to capture maximum sunlight throughout the day.

2. Window placement.

Heat loss in winter occurs through windows, so size and placement is important. Double-glazing is also beneficial and becoming more popular, meaning it’s cheaper than ever. Our home is traditionally styled, with a wrap-around verandah to shade rooms from harsh summer heat, so it’s a good idea to place eaves or a verandah over north-facing windows so they’re shaded during summer. We’ve also planted deciduous grape vines against the pergola at the back of the house to provide additional shade; if I can stop the caterpillars from munching them!

3. Natural ventilation.

Ventilation is so underrated!  Work out which direction summer breezes come from, then place doors and window to capture and direct it through the house.  Great ventilation reduces the need for air-conditioning, reducing your electricity costs considerably.  Where we live in Little River is very flat with prevailing winds from the north-west, so it’s easy to cool the house by opening two or three windows at opposite ends of the house. Ceiling fans also help circulate the air.

4. Insulation.

Exterior wall and ceiling insulation is a given, but you can also consider insulating between the zones of your home. Our bedrooms are in one end of the house and living areas in the other, so by insulating the bedroom zone we can keep them at a comfortable temperature, even though we might have doors open elsewhere.  Simply using good insulation can add a couple of stars to your energy rating!

There’s a wealth of information online to assist you with your new home plans, as well as showrooms, expos and home shows you can visit to get professional help.  Check out Green Homes Australia and Sustainability Victoria for lots of information to get started.

Want to find out more? Join the conversation at agl.com.au/community.