The project wasn’t about to be a run-of-the-mill, low-cost home for the couple, with both of them engaged in environmentally conscious careers. Shay still works with solar technology and Jo is employed in sustainable design.
They both feel strongly about sustainability and have made lifestyle choices to personally walk the talk. The couple are committed to having a home that’s healthy for the occupants and the planet, which suits their needs and rather than focussing solely on the financial return on their investment.
Don’t be fooled into thinking Jo and Shay are new-age, hemp suit wearers building a tree house in the bush. The project involves a collaborative approach between themselves and their architects Jennifer Hanson and Kendon McGrail from A Design Studio, as well as numerous hours researching the performance rating of materials and design details. Jo thinks sustainable building practices in New Zealand are probably about 10 to 15 years behind the UK and the couple knew what could be achieved by building their own home rather than buying an existing property.
They have launched a website www.zeroenergyhouse.co.nz to share their experience with other likeminded house builders. The philosophy is to provide information for people to pick up ideas from their project and to demonstrate building to best practice rather than meeting minimum standards of regulatory building codes.
“The cost of building here is a lot cheaper than the UK. Timber frames are very common and it’s easy to source timber here, but in the UK double brick walls are used a lot. They use more materials and do a more detailed build than we do here,” says Jo.
Shay adds that building houses to minimum standards sets a benchmark for construction projects that ultimately drives down the total market because people demand competitive prices.
As an architect, Jennifer was attracted to Shay and Jo’s project because it is a low-cost, first home with clients who wanted a healthy house with low running expenses. The zero energy house balances initial capital expenditure with ongoing operational expenses such as heating, power consumption, waste disposal and transportation.
Dealing with the council is an ongoing concern for the couple and they are trying to get them onboard early in the process. Jo and Shay don’t want to bear the high cost of the council’s initial approval process of sustainable technology that is new to New Zealand but has been successfully used overseas.
Innovative systems to manage grey water on the property and to integrate a photovoltaic (PV) system into the roof are stretching the resource consent boundaries. Shay’s expertise lies in PV systems, which convert light into electricity but the technology is uncommon in New Zealand.
“On a bright sunny day you get 1000 watts of free energy from the sun at any one point in time,” says Shay. “Internationally there are many PV products that double as the roofing material, but in New Zealand there is only one that I know of.”
There is also the challenge of using locally sourced materials that are familiar to builders and have reduced transportation cost as opposed to unfamiliar products that need to be imported.
Jo is qualified and experienced in materials engineering and advanced computational methods and has completed extensive thermo-modelling of the house to ensure it works efficiently. With the website they are hoping for a feedback loop and the theory will be compared to the reality.
“It’s important for everyone to see what happens onsite and whether it’s actually working. There will be a stage after [the build] when we hope to monitor the house to make sure it’s working energy efficiently and it’s warm enough.”
The couple intends to live in the house for a number of years and the floor plan is designed to meet their needs as well as sustainable principles. The ground floor has 1.2 metre overhangs that provide cooling shade in summer but let in winter sunshine to use passive solar energy to heat the polished concrete floor.
“We thought about having a double garage because it’s better for resale and people expect that, but we decided, no – that’s not exactly what we want to achieve and it’s not right for us,” says Shay.
Good planning and patience will minimise building waste, which impacts on the budget and the environment. Making late changes is always costly.Building is expected to commence by the end of 2010.
“I think sometimes people see these type of houses as hippy houses that you’d find in Titirangi rather than Howick. But we see it as something that everyone could benefit from. It’s warm, comfortable, cheap to run and if you build it well, it will last a long time,” says Shay.
Common sense, new technology and commitment to long-term goals make sense, but it still proves challenging when quick capital gain is a higher priority than the function and health of a home.
To watch the progress of Shay and Jo’s first home, log onto www.zeroenergyhouse.co.nz.
