Auckland's Jessop Architects has developed plans for passive houses with extremely low energy consumption.
Darren Jessop said he wants to raise awareness about the concept and a $160,000 Titirangi house, about to be built, was a good example, he said.
"It's a 24sq m one-bedroom crib-style retreat, with a bathroom and kitchen and it's how to get all the main functions into one small space, and make it low energy," he said.
The small place in a cool bush setting was for a client who wanted a retreat from the bustle of the city.
Passive houses are well insulated and virtually airtight and the main form of heating is via passive gain.
"This means that the building's interior climate can be maintained at a comfortable level without active heating and cooling systems," he said. "A passive house combines high-level comfort with low-level energy consumption using ... insulation, thermal windows and heat recovery."
Take a look at more Coolhouse designs by Jessop Architects: