Kiwi firm designs low-cost, fast-build house

A New Zealand architecture company has designed a three-bedroom house that three people can assemble in six weeks for $335,000.

RTA Studio just constructed its first 'Living House' in Rotorua.

It is 85sqm and designed for quick assembly once the foundations are in place, the cost includes a functional kitchen with appliances as well as flooring, lighting, carpets and heating. It does not include the land value.

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The company wants to market and sell the Living House plans and access to pre-negotiated supplier packages to anyone who wants to build – including community housing providers.

Frustration with the failure of successive governments to get to grips with the housing crisis was the motivation behind Living House, founder Rich Naish told RNZ’s Nine to Noon.

“We just thought, look, we've got some bright sparks in our practice. Why can't we sit down and really unravel this problem and solve it?”

Stripping out labour costs is the biggest contributor to the affordability of the concept, he says.

“We did some research and found that 40 percent of a typical New Zealand house, that cost is labour, and so we set about to try and optimise the building process and materiality of a house so that we could strip that labour out, and we've got it down to 10 percent.”

The basic structure is made of made of CLT (cross laminated timber) panels, he explains.

“It's really just a matter of 36 panels that get tilted up a bit like a flat pack furniture package that goes together in about three or four days.”

The design reduces the hours trades spend wiring and plumbing, he says.

“A traditional house has a first fit of wiring and a first fit of plumbing, and then the plumber and the electrician come back and do their second fit-off.

“We've worked out a way where it can just be a single fit, so the electrician can come along and pretty much do their job in a couple of days, the plumber in a couple of days.”

Reducing complexity allows for this quick turnaround, he says, taking out the need to feed cables and piping around and through difficult routes.

“We've pulled all of the plumbing together into one spot. A couple of holes get drilled, it all gets reticulated under the floor, which is suspended off the ground.”

He estimates this takes hours off the trades bill.

“How can we turn a 40 or 50 hour job into a five or a 10-hour job?”

The CLT is manufactured in Rotorua from locally grown pine, Raish says.

“It's about 120mm thick and it's produced in a plant in Rotorua, Red Stag Timber has a large plant there.

“It's New Zealand grown wood, it's made down the road. It can be transported anywhere in New Zealand on one truck and lifted into place with a with a truck crane.”

Cladding is again a traditional material, he says.

“It's just good old fashioned corrugated iron, but it's a high performing powder coated one. And the reason we've used that is that it allows us a really fast, labour efficient way of putting that on the roof and on the walls.”

The house has a four-meter high stud in the living, kitchen and dining space, he says.

“Even though it's only a 85 square meter house, it has an immense feeling of scale and light and airiness.”

RTA partnered with Fisher and Paykel for the heating and hot water system.

“It's all efficient heat pump-powered systems. The hot water cylinder runs off a heat pump, the air heater off a heat pump which run off solar panels.”

The house has a multi-proof consent, pre-consented from the floor up, he says.

“We can't consent from the floor down, because every site is different. So, each project will have a little mini consent for its foundations.”

There's no bells and whistles on the house but it can be jazzed up, he says.

“We call it the Toyota Corolla version. You can always pimp it and add your mags and your fluffy steering wheels later, but it has everything that's fit for purpose, for best practice, for warm, healthy and dry homes.”