Building for a better future

SHAC national co-ordinator Tim Bishop (foreground), with, from left, Otago Polytechnic administrative assistant Tracey Paul, polytechnic carpentry tutor Matt Thompson, polytechnic executive projects co-ordinator D'Arcy Dalzell holding her daughter Zadie Tarbit (9 months), polytechnic graphic design student Simon Horner and University of Otago energy studies student Maria Callau and her daughter Maia Puricelli (4). Photo by Linda Robertson.

• The SHAC '09 entrants

Let's deal with the difficult bit first.

What is sustainability? Once the preserve of those perceived as "greenies", the term sustainability has become a buzz word particularly well-used by teachers and politicians.

It can mean different things in different contexts, but a useful layman's definition is this: sustainability is putting as much back into the environment as you take out - in other words, meeting the needs of the present without compromising the ability of future generations to meet their needs.

For Tim Bishop, the Sustainable Habitat Challenge - cutely known as SHAC - is all about coming up with innovative ways New Zealanders can live well while being free from reliance on expensive resources.

That means houses which are better insulated, cost less to heat, use the most efficient building methods possible, and are not too expensive to construct.

It is also about collaborations, where teams tap into the expertise of others in this country and overseas and explore what is practical and possible to build today, Mr Bishop says.

"It is fantastic to see people working together already . . . discovering ideas which will work and ones which can't yet.

For example, one team wanted to install a grey water system in their house which would reuse water but found it was too expensive to do today. [However,] they are discovering what it will take to be able to install such a system in the future."

One of the aims of the challenge is to promote business opportunities, as designers worked with New Zealand suppliers and manufacturers to source or make products unavailable in this country as yet.

One team doing just that is Team Waikato, a collaboration between the Waikato Institute of Technology (Wintec), a private businessman and the Hamilton City Council's eco adviser.

It will use two products new to New Zealand in its 60sq m transportable cottage.

The walls will be constructed of panels consisting of soy-based foam sandwiched between sheets of plywood, while the exterior cladding will be Australian-made weatherboards manufactured from waste eucalyptus bark.

The businessman behind the panels has been trying to introduce the system to New Zealand for many years, lead designer Rod Yeoman says.

The panels, which would use plywood made of New Zealand pine, were lighter, stiffer, had much better insulation qualities and were much quicker to put together than a traditional timber-framed house.

But because the system is untested in this country, no building code is available and it had proved time-consuming to obtain consent to use it.

"It's been a really interesting roller-coaster ride.

Because of the multilayered approach we have adopted for construction, institutions and local authorities have found the consent process complicated.