Timber-home innovators push the 'thermal envelope'

Joe La Grouw with one of the company's new EcoSmart houses in Rotorua. Photo / Alan Gibson

New Zealand's iconic Lockwood Homes, which make extensive use of locally grown timber, have arguably been eco-homes since they were first built more than half a century ago.

Lockwood chief executive Bryce Heard says the wood used in construction is storing carbon that might otherwise be released into the atmosphere through other end uses.

"To produce wood also takes a fraction of the energy footprint compared to smelted products like steel."

Mr Heard said Lockwood thought it could do better, however, and wanted to address increasing concerns about climate change and the environmental impact of building and construction.

It has launched a new range of EcoSmart homes, which use more wood and increase insulation with architectural designs to help create a "thermal envelope" within living areas.

The eco-homes further incorporate a solar tower to get the best position for solar water heating and a north- facing beak to support solar photovoltaic cells for electricity generation.

Special acrylic paint is used to reflect excess heat while panelling, a sunroom, tilt doors and extensive use of floor tiles aim to trap daytime heat.

Mr Heard said New Zealand-grown radiata pine is used for all floor and roof framing, ceilings, slats and weather boards. The timber joinery is Tasmanian oak sourced from sustainably managed forests.

Mr Heard told the Herald at the launch of the new range at Lockwood headquarters in Rotorua that the company decided to pursue the eco-range after market research confirmed consumer demand.

"There is a group of people with discretionary spending power who have a social conscience and environmental awareness and want to do the responsible thing."

Mr Heard said there had already been inquiries about the new designs, which would cost between $200,000 and $600,000 depending on size.

He imagined they would be popular on lifestyle blocks but anticipated many of the houses would also be built in standard residential areas as they could be adapted for individual sites.

Mr Heard said that in producing the EcoSmart series the firm shifted away from its priorities of looks, cost and the convenience of construction to focus on environmental soundness.

He estimated the EcoSmart houses are about 15 per cent more expensive than others of similar sizes in the Lockwood range.

Mr Heard said that when comparing the benefits of the construction materials alone, the EcoSmart energy consumption was about two-thirds of that of a house built of conventional materials.

"It is a lower-energy process to use wood rather than steel, aluminium or plastic."

Lockwood founder Johannes La Grouw, aged 95, said he was impressed with the new designs.

"It is completely different ... We had to do something."

His son Joe La Grouw, Lockwood's chairman, said the company had always been innovative in meeting challenges.

"The organisation still does things differently, pushing boundaries ... Our eco-homes are an example of where things are going in the future."