If passive solar design is so good why isn’t everyone doing it?
Here at Strine Environments, we are sometimes asked by new clients why, if passive solar design is so good, isn’t everyone doing it? To which we say good question!
We believe it comes down to a few key issues, which revolve around a lack of education and misconceptions.
A common misconception is that if a house is sustainable, then style will have to be compromised. Surely they can’t coexist because eco-friendly, green energy homes are the provenance of dyed-in-the wool greenies who are not concerned with sharp, contemporary architectural design. Right? They just want to save the planet, which is all well and good, but surely it can’t be beautiful too?
Well leaving the stereotypes that surround ‘greenies’ to one side, the answer is of course no.
Strine’s passive solar designed homes have been fine-tuned over many years by owner and director Ric Butt, a highly awarded architect in Australia and internationally. Strine’s homes are about creating comfort for the owners by keeping the inside temperature close to 20º in winter and summer, but the science that goes into this is not visible to the naked eye.
To achieve year-round temperature stability, we have developed our own insulated precast concrete panels that allow us to provide high performance thermal mass. If you went into a Strine home you wouldn’t be able to pick if the walls were concrete or plasterboard as you have the option to paint or leave them with a natural finish.
We can talk nonstop about the critical role of thermal mass, ‘earth coupling’, the importance of insulation, what correct glazing looks like, and even the importance of landscaping to a Strine home. Some people will find this fascinating while others will start to feel their eyes glaze over. The bottom line is a Strine home offers not only exceptional energy performance but great architectural design as well.
You don’t have to evangelistic about saving the environment to see the overwhelming benefits of a passive solar design Strine home. If people realised that passive solar design is not expensive to build, can be contemporary and stylish, fast to construct and, perhaps most importantly, completely eliminate heating and cooling bills, there’d be a lot more interest.
At the end of the day, we at Strine have to do a better job at explaining the huge benefits of our passive solar designed homes. The typical brick veneer homes that dominate Australian suburbs passed their use-by-date a long time ago. They never suited our environment but they are the norm because that is what builders know how to build, and they are what most people expect to live in. But long-term, they are the most inefficient and expensive option when it comes to energy costs, which can make up 50% of the costs of a building over its lifetime.
Eliminating energy bills
Tell people you can eliminate paying for heating and cooling in Canberra’s climate of extremes and they are amazed. But it’s exactly what you get from a Strine home. In the recent heat wave conditions of early 2014 where temperatures reached the mid 40s, our houses did not need air conditioning to maintain a constant temperature of around 25 degrees. And in winter they maintain a constant temperature of around 22 degrees with some supplementary heating on cloudy days. This is important as the cost of electricity rose approximately 94% between December 2007 and March 2013.
In our Harrison house case study, calendar year, they only paid $1350 on electricity and gas, which was used for cooking, running the dishwasher and for hot water in two bathrooms. They didn’t pay anything for heating or cooling and in fact their gas bill that winter was only $250.
For some, it’s about eliminating energy bills when gas and electricity are just going to get more and more expensive, and treading lightly on the environment is just an unexpected bonus.
What is passive solar design?
Strine Environments’ passive solar buildings revolve around four basic principles:
- Building the house so it faces north to maximise winter sun, and eliminate summer sun with a vine-covered pergola.
- Creating thermal mass on the inside in the floors and walls through our precast concrete panels that absorb winter heat and slowly release it in the evenings.
- Putting a doona over the house at night by building high-level insulation into wall panels and the ceiling, as well as around the floor slab.
- Correctly glazing different aspects so the sun is either absorbed or reflected.