Learning about a property
To get the home they wanted, Julie and Matt started with a carefully chosen site.
“Before we bought, we made a list of priorities,” says Julie. “We wanted a rural home that was energy efficient and great to live in. We also wanted to have good access to commuter transport, a reliable water supply – either from waterways or rainfall – and established trees.”
Being clear about their priorities made it easier to choose. “Compromises are inevitable,” says Julie. “You can’t get everything you want in a property.”
After searching for nearly 12 months, they found a rural Wairarapa site that met most of their criteria, and also had the benefit of great mountain views. Once they’d bought it, their priorities were:
- designing a home that would use energy and water efficiently while also being sympathetic to the site
- preserving and enhancing a nearby stream and mature trees
- access to views
- managing exposure to prevailing north-westerly and south-westerly winds
- using building systems and low-toxicity materials that minimised contamination of soil and ground-water
- access to mains power.
Their first task was to understand the property’s main features in terms of microclimate, weather patterns, neighbours, and topography. Though the highest point on their site provided the best views, their architect encouraged them to compromise and locate their house on a north-facing flat area downhill from the highest point.
“The north-facing site gave us good access to sun,” says Julie. “It was also further from the neighbours, and provided shelter from cold southerlies by using a large stand of trees.” Their architect, who had experience in designing energy-efficient buildings, used sun path data specific for their location so he could advise on how to orient buildings to make the most of the sun’s energy. This helped Julie and Matt to site a shed so the roof could subsequently be used for photovoltaics, and to orient the main house so it could use solar water heating, and passive solar design, while retaining the view.
Learning about the site
As well as spending time on the site, Julie sourced weather information from NIWA, and local weather stations provided information on wind speed and direction, plus annual rainfall and sunshine patterns. “The prevailing wind and rain meant our dream of building a straw bale house wasn’t a good option,” says Julie. “So we changed to highly insulated conventionally clad timber construction instead.
As well as getting climate data, we talked to locals who had been unsuccessful with straw. And we realised that, because of the thick walls and large eaves, straw wouldn’t work very well with passive solar heating. So we used it on the south side for insulation.”
The design they settled on used materials and form that ensured the building was sympathetic to the site and echoed the colours of the surrounding vegetation. The design also used local and sustainable materials wherever possible, so rocks from the property became a design feature.
The free-draining nature of the soil and the slope of the site towards a stand of trees influenced decisions on the type of waste treatment system. “The local council would have let us use a basic septic tank, but we wanted to invest in a more sophisticated system that wouldn’t leach solids in high rainfall and would deliver greywater onto the trees without contaminating groundwater.”
Because they’d researched rainfall, Matt and Julie knew that rainwater would be sufficient to supply their domestic needs, so that no bores or streamwater would be needed. “The decision to rely on rainwater emphasised the need to make sure our appliances and planted areas used water efficiently.”
By prioritising sustainable and re-used building materials, and requiring local builders to monitor material use to minimise waste, they saved nearly $25,000.
All earthworks were re-used on site to create mounds for shelter from wind.
What did they learn?
“Talk to other people with experience and do as much research as possible,” says Julie. “Our architect provided valuable advice on how we could best use the site, and we tried to find local examples of sustainable building to learn from as well. Be prepared to compromise your dreams if they are not practical for the location and the climate.”
Another lesson was to be aware of the impact that neighbours can have on your site and how you live on it – for example, because of privacy considerations, noise, views of buildings, appropriate boundary plantings, and ongoing development of surrounding land.
Though theirs was a rural site, Julie says the lessons they learned would also apply to urban settings.
“You can only make decisions based on the best knowledge you have at the time, so taking the time to research your options, and not accepting everything tradespeople tell you, is really worthwhile!”
