How to live in your house

Rooftop with solar panelsSaving water and energy is a consistent element of the every sustainable house in Australia. But sustainable houses are often stereotyped as unusual, as if the houses and their inhabitants are somehow not like the rest of us and have achieved something we cannot do. And yet over one million houses in Australia have solar panels and 2.3 million houses have a rainwater tank. The following home owners show that caring about our impact on the planet and the future for our children puts money in your pocket and is easily achieved with existing technology. 

In 1996 Michael Mobbs renovated an inner city terrace house in Sydney. He and his wife did a great job with non toxic materials, efficient appliances, cross flow ventilation, installing solar panels, rainwater harvesting, a water treatment plant and stormwater retention. Michael drinks rainwater and regularly tests it to demonstrate compliance with the Australian Drinking Water Guidelines. In the two decades since Michael’s four person family have spent less than $300 each year on utility bills, saved 2 million litres of water, and the same amount of sewage from going into the ocean, prevented all stormwater from leaving their property and saved 80 tonnes of coal from being burnt. Was it difficult or expensive? Not according to Michael in his excellent book about the project.

In 2002 Professor PJ Coombes renovated an inner city Newcastle Terrace in Carrington. Professor Coombes installed  rainwater tanks, solar panels and water efficient appliances. Professor Coombes has kept meticulous records. The rainwater harvesting system cost $2350, combined with water efficient appliances the cost of water savings was $0.12/KL. Professor Coombes reduced his use of mains water by 78% and his electricity bills by 61%. Professor Coombes uses standard off the shelf commercial technology.

This was not Professor Coombe’s ultimate contribution however. Professor Coombes saw that conventional analysis of rainwater, water and energy was looking at the trees, not the forest. Taking a systems view Professor Coombes has carefully documented the cumulative impacts of household decisions on water and energy use and the impact at a regional scale and the billions of dollars in infrastructure that could be saved. Professor Coombes and Michael Mobbs used their experience to convince the NSW State Premier to develop the BASIX program, the most successful sustainability housing program in Australia.

In 2012 Josh Byrne started building Josh’s house in Hilton near Fremantle in WA. The two buildings use solar panels, rainwater, greywater and borewater and provide kitchen garden produce as well as a high amenity landscape. “The (10 star) houses have been built at a similar square meter cost and time frame as more conventional 6 star homes using readily available materials and technologies.” (http://joshshouse.com.au/). This is what the astute householder should be taking into account, this house uses 90% less energy and greenhouse gas than a conventional household and two thirds less water despite a productive garden. The houses were completed on time and on budget. Since then Josh has upgraded to an electric battery storage system with his solar panels to almost completely eliminate grid electricity use. Josh also details some other star performers on his website. Josh also makes the important point that his comfortable, beautiful home is a pleasure for him and his family to live in.

Annual electricity use and generation graph

Why have we focussed on these three houses? Because all the builders carefully researched the projects before they built them, they documented the costs and problems and they published the results.  They thought this issue was so important and so simple to apply they provided details and reporting, free of charge, for others to use and copy. Josh asks ‘Why arent all houses built like this?”. We could all be asking this question.