Sustainable building can wow buyers. Although some buyers just want value for money, a sustainable healthy home is an added bonus marketing bonus.

The thing to start with, says Andrew Eagles, chief executive of the New Zealand Green Building Council (NZGBC) is insulation, ventilation and safe and efficient heating. "Forty per cent of New Zealand homes are damp or mouldy," says Eagles. That is confirmed by the BRANZ House Condition Survey.

Buyers are particularly interested in whether homes are healthy, says Eagles. "That is front and centre for most people."

If you want to find out whether the brand-new home you're buying is truly healthy, says Eagles, look for the Homestar rating. Homestar is an independent rating tool that measures the health, warmth and efficiency of houses.


The New Zealand Building Code equals a Homestar 4 (out of 10) rating.

The Homestar 6 rating means a home is 20 to 30 per cent warmer and healthier than an equally nice-looking house that simply complies with the building code.

Ratings of six or above have become a selling point for new homes. For example, Barfoot & Thompson agent Barry He has been advertising a "6-Star Treasure in Westgate".

The words "6 Star" relate to the Tihema Lane property's Homestar rating. Many of the new homes going up in and around Glen Innes are also Homestar 6 rated.

Too many second-hand homes have insufficient insulation and still use unflued gas heaters. Mechanical ventilation (extractor fans) is needed in kitchens and bathrooms.

The NZGBC is developing a new standard called HomeFit for second-hand dwellings.

Homeowners will soon be able to employ an accredited assessor to evaluate whether their home passes the test.

Homeowners can also market the water and energy efficiency of their homes. There are sustainable taps and showers on the market from Methven and others that significantly reduce water usage, says Eagles.

And replacing existing lighting with LEDs will reduce electricity usage and appeal to buyers.

Another selling point for a sustainable home could be the use of low VOC (volatile organic compounds) paint. VOCs are harmful chemicals found in paint, says Eagles. Yet paint suppliers now offer VOC-free paints.

Several paints from Resene, PaintPlus, Wattyl and Dulux sport the Environmental Choice New Zealand tick.

Upgrading the heating systems is both sustainable and a good marketing point for selling a home. Properly installed wood burners are particularly efficient, says Eagles.

The thermal efficiency of windows can be improved with double glazing, low-e or the creme-de-la-creme of "thermally broken" windows where both the frames and the glass reduce heat loss.

Solar panels area also popular with eco-friendly home buyers. But creating a passive home is more important from a sustainability point of view, Eagles says.