Mt Lawley House – the Power Bill Test!

You hear a lot about sustainable houses and sustainable technologies, but with so much out there claiming the ‘sustainable’ title it really pays to look at the facts and data to see just how effective these things really are. At our recently renovated Mt Lawley House (Have you seen it yet? The mind-blowing transformation has been documented here) they have just received their first power bill and it is a joy to see how their power bill compares to the average. Their bill is almost $100 cheaper than the Mt Lawley average, but more accurately, their bill is about 33% less than those of similar sized homes.


What is responsible for this reduced power bill? It is a combination of features of the house and inhabitant behaviours. On hot days, the house is kept shut up, while at night the Velux highlight windows are opened to purge the house of any hot air. All the original windows of the house were enlarged to increase natural lighting, meaning that lights are never needed during the day. The windows are double glazed Britone windows, to reduce the heat transfer. Throughout the Summer, ceiling fans were used to keep the house cool, with the airconditioning only ever turned on three times for a few abnormally scorching days. The roof space was significantly insulated, with not only a lining under the roof, but the ceiling was insulated as were vertical elements connecting the ceiling and roof to create a sealed space. Appliances were consciously selected for their performance, for instance the Stiebel Eltron hot water heat pump was used in the house for efficient water heating. All of these contributed to the reduced energy usage of the house. As they say – the proof is in the pudding! We hope that this can give you an idea of the kinds of things you can do in your home to reduce energy usage, and how these can impact your bills.