Momentive and Energy Plant Solutions this week won the large business category of the EECA Awards, handed out by the Government's Energy Efficiency and Conservation Authority, with the judges saying the project turned a liability into an asset.
The two companies shared a second award, for innovation, with Ngati Hine Health Trust.
The Northland trust was recognised for its Te Mirumiru Early Childhood Education Centre at Kawakawa, featuring a green roof formed by an earth mound. The design is 67 per cent more energy-efficient than a standard building.
Architect Phil Smith said the brief for the $2.5 million centre was a mix of cultural and sustainability goals. The earth bank played a passive heating role as well as being a "womb-like" element.
"It's very symbolic like a lot of Maori architecture, but in a modern way."
The building had underfloor heating using piped water that was warmed by solar roof panels.
It was a technically outstanding building and a landmark for Kawakawa, the judges said.
• The Herald is an editorial partner of the Energy Efficiency and Conservation Authority Awards.