Green homes go mainstream as costs climb

Houses with solar panels and other energy-saving features are becoming more popular around the world. File Picture / Paul Estcourt

Hippy havens with solar panels and rain water tanks are no longer the stuff of the fringe and are quickly becoming more popular as high power and water prices start to hit people's pockets.

The revenue of New Zealand's oldest energy business focused on sustainability in the home, Negawatt, has doubled in the past 18 months as a result of this growing awareness, says owner Grant Dunford.

Overseas, the Chinese solar company Suntech Power raised US$400 million ($632 million) in December, and its share price has since shot up 50 per cent. The world's largest wind-turbine company, India's Suzlon Energy, was 28 times oversubscribed when it launched for US$340 million at the end of last year.

New Zealand's Negawatt was founded in 1992 by Dunford, influenced by the work of Amory Lovins of the Rocky Mountain Institute in Colorado.

The company has its work cut out in New Zealand, where most of the houses are not built to take advantage of the sun, and are greedy harbourers of mildew.

Negawatt has what it believes to be some cutting-edge eco technology for the home, but it needs to be installed as part of a system of maintaining the "health" of the house, says Dunford.

"You want to have a house that breathes, and can achieve air-flows in the house. Houses are being built so that they are air-tight, and emissions from the building materials build up in the air. To get the insulation right in the home is the key.

"It is about understanding the science of the product, and educating people about the energy performance and health of their house."

The company installs mechanical heat exchanges in roof cavities for an average price of between $4,000 and $5,000, and twin foils with polymer bubbles in between that provide insulation around the house.

"The technology recovers its cost six times by maintaining the house in a dry environment," says Dunford.

As power prices shoot up, many alternative eco technologies are starting to surface in the marketplace, and people are flooding into the industry.

"But many people don't really research the products or understand them, so it pays to be careful."

Lovins, the doyen of eco living, is the co-CEO of the Rocky Mountain Institute, a non-profit natural resource think-tank. He lives in the Rockies on an unusual banana farm.

Newsweek called him "one of the Western world's most influential energy thinkers". His 1200sq m house in the Rocky Mountains is a working model of what he is aiming for.

Though temperatures can drop to -8C and frost can form most of the year, the house runs on the amount of energy it takes to fuel one conventional light bulb. Enough to make power companies quake in their boots.

This is mainly due to good insulation, and a central, sun-filled atrium.

According to the Rocky Mountain Institute - which has been one of the main influences of Negawatt in New Zealand - buildings use most of our energy and deplete vast quantities of natural resources.

They pollute water, earth, and air and can harbour unhealthy indoor environments, while green developments typically demonstrate sustainable practices of elegant design, offer responsible stewardship of the natural environment and make wise investments.

Lovins has been behind a major push for corporates to go green, and it is working. American shopping chain Wal-Mart has employed the Rocky Mountain Institute to help it reduce fossil fuel consumption in both transportation and retail stores.

Back home, people are becoming more aware of green technologies for the house, and so are New Zealand's budding architects.

The University of Victoria in Wellington is running a course focused on making building materials from waste projects including plaster board, treated timber, and other construction and demolition waste materials. This prevents the use of more new materials and avoids the dumping of old ones.

It is thought that about a third of New Zealand's waste comes from the construction and demolition industry, a huge component of which is plasterboard.

An exhibition of the students' work will be held from September 5 to 12 at the School of Architecture at Victoria University.

An organisation in the US called Earthship oversees the building of houses made of car tyres, filled with compacted earth to form a rammed earth brick encased in steel belted rubber.

In the UK, technology company BubbleDeck recently launched a product featuring recycled plastic hollow bubbles which can be placed in the middle of a concrete floor to support the concrete slab's weight.