When the opportunity came up to build a new house from scratch we* decided to implement our passion and build a “Solar Passive” style of house. Lots of big windows facing north for light and winter heat. Cross flow ventilation to cool it down in summer and big verandas to shade the big windows. Plus, a concrete slab to soak up the winter sun and keep it cosy. We did not have a specific plan, but knew it would be a simple pavilion style of layout. And, compact, and, we want to be able to live in it for as long into our older age as possible. We reckoned we should be able to get an 8 Star house that delivered those outcomes.
But, we also knew that we needed a builder who thought along the same lines. And we found him doing a job just around the corner. We could see from inspecting his work that he was a stickler for detail. We liked that. So, we engaged him to be our builder before we had the house plans drawn up, and he agreed to work with us (and a yet to be appointed designer) to design a comfy and compact 2 bedroom home.
Then the surprise came! He told us about the added benefits of adding a “Passive House” overlay to our basic solar passive ideals. And, we agreed. Not only because he is an accredited Passive House (PH) constructor, but we could see the long term benefits of a really low energy house. The PH add-ons are essentially super insulation to the external skin of the house (floors, walls and ceilings), creating an airtight interior (no draughts) and supplying filtered clean air into the building at times when all the windows and doors are closed. This was great during the bushfires and the recent cool burns – we could live inside and not smell smoke. We know how much these add-ons costed. Not a lot really.
We also know what we did not have to spend. No open fireplace or wood heater. No large reverse cycle air con – the first retailer we spoke to in Bairnsdale wanted to sell us an 8kW system. We only needed 3kW. He would not sell that one to us because he feared we would claim damages against him when it did not work.
Going down the PH path added about 10% to the building cost. But without spending that bit extra, we would not be getting an annual refund from our electricity supplier of $500. And, no firewood to buy. Overall, we achieved a super low energy house (it is all electric) powered by solar PV and a grid connection. It performs better than we expected. And it did not break the budget.
*The author, and his partner Fran Carroll. They are members of the Metung Science Forum