Sustainability is the key

LET THE SUNSHINE IN:Houses oriented towards the sun help trap heat, like this one on Waiheke Island.

Mid-winter 2005 will mark the end of the Ministry for the Environment's year-long Warm Homes Project.

It is a nationwide project that follows the new environmental standards for air pollution introduced last year.

Second only to vehicle emissions, home heating has been identified as a major contributor to air-borne pollutants, and in response the project is looking at our heating habits and ways to encourage households to choose cleaner options.

"Different communities have different heating needs,'' says Martyn Pinckard, spokesperson for the project, adding that councils will be responsible for implementing changes and cleaning up the air in their region.

To tackle the problem, the Auckland Regional Council (ARC) will ban installation of non-approved wood burners from September, pending an appeal.

Taking their place are a new generation of low-emission wood burners designed to reduce the level of toxins released into the air, and setting minimum efficiency requirements at 65 per cent, compared with the 15-20 per cent effectiveness of an open fire. The new models have a system that pre-warms the oxygen entering the fire, causing it to burn hotter and cleaner.

David Bell, spokesperson for the New Zealand Home Heating Association (NZHHA) says the new wood burners work well as long as people are burning dry wood.

New Zealand homes have traditionally not been designed for energy-efficiency or to maintain warmth, and are often poorly insulated. Robert Vale, lecturer on sustainable building design at Auckland University's school of architecture, has designed houses that require no heating. He says there are two main considerations when building houses to make the best use of energy.

The building must orient towards the sun, with most of the windows on the sunniest side. Once the heat is inside the building it needs to be trapped by extensive insulation. "Everything should be insulated - the walls, the floor, the ceiling - beyond the specifications of the building code, and windows need to be double-glazed to stop heat escaping.''

Vale also recommends an electric heat pump as the most efficient and low-impact way to heat a home. This is a standard air-conditioning unit and, while using it to cool during summer consumes a vast amount of power, if used solely as a heater it pumps out three units of energy for every one that it uses.

As one of the most popular heating methods, gas is a non-renewable fossil fuel and therefore is also environmentally problematic.

Vale suggests that an effective way to use gas to heat a home is to use it to fuel a central heating system. If used in conjunction with a condensing boiler, it proves more efficient than if the gas was burnt off at a plant.

Heather Staley, CEO of the Energy Efficiency and Conservation Authority (EECA), recognises that our energy use is often habitual, and changing peoples' ways could prove to be the biggest challenge in the wake of the Warm Homes project.

Legislation such as the ban on new fires is one way to force the public to become more environmentally responsible, but organisations such as the EECA have come up with a range of positive initiatives to encourage people to make changes of their own accord.

They have developed a rating system that allows consumers to compare the efficiency and running costs of appliances, and a way of projecting that cost over the life of the product, bringing energy efficiency to the fore when people are deciding what to purchase.

EcoMatters is a not-for-profit charitable trust working in partnership with the Waitakere City Council, which also runs a number of initiatives to bring energy efficiency into the mainstream.

They're involved with providing show homes and information on building and appliances to help raise public awareness of sustainable building options.