Australian Passive Solar Home

I think the single key question to ask before settling on an approach to energy-efficient home design is this: “What will the proposed home cost to build?”

There are numerous approaches to energy-efficient home design that are expensive e.g. in Australia, Passivhaus is one of them. In fact, I think it’s very easy to build an energy-efficient home…if cost doesn’t matter much. After all, architects seem to do it every day of the week!

The challenge comes if you want good energy efficiency at no extra cost over building a conventional Australian home.

I’ve heard many people professionally working in the energy-efficient home space sneer at normal Australian houses – “Why would I want to build a crap house like that?” they ask. Well, the answer is easy – because of cost. When we have an absolute crisis in housing costs, where many young people will probably never own a house, cost must be the starting point.

So is it possible to build a new cost-effective, energy-efficient home in Australia? Yes it is – but the starting premise must be: how can each feature of a home be optimised for better energy efficiency at no extra cost?

What we then have are the fundamentals of passive solar design:

• orientation (the direction that most windows face)
• thermal mass (the energy storage capability of the internal house structure including the floor)
• shading (including that provided by eaves)

Insulation and sealing need be no different to that provided by any current new build where attention is paid to detail. So, if the home design is picked or developed carefully, the extra cost will be zero.

To reduce cost still further over a current Australian home, keep the design simple – so many current Australian builds are inordinately fussy and complex.

It’s possible to build highly energy-efficient homes in Australia – but unless the home is being built for the wealthy, the starting point for all decisions needs to be: what will this home cost?