Is your home a star?
The Homestar certification rates homes according to their environmental impact. The higher the rating, the better they are – for people and planet.
Lurking in the fine print of the Draft Auckland Unitary Plan is a proposal for new dwellings to be built to a Homestar 6 standard, if five or more consents are sought at once.
Homes built to current building code minimum would get a Homestar rating of around four, so it’s a jump. What will it achieve?
“You’d notice. There’s a hell of a difference between 4 and 6,” says Homestar director Leigh Featherstone.
The Homestar rating system was developed in 2009 by the New Zealand Green Building Council and building industry research body BRANZ.
It’s New Zealand’s only independent, verified residential sustainability rating tool, establishing a common standard and language to describe the environmental performance of New Zealand homes.
Almost half the credits in Homestar relate to energy, health and comfort, which is mostly about the thermal performance of the house.
To reach a rating of Homestar 6 out of 10 the house must include total insulation, double-glazed windows or heavy-duty thermal curtains, energy efficient lighting and appliances, and water efficient systems such as low-flow showerheads and dual flush toilets.
“That means it should be a warm, well ventilated house that doesn’t have mould, doesn’t have condensation, and will keep you healthier,” Featherstone says.
An independent study has estimated reaching Homestar 6 adds just over two per cent to the build for a standard three-bedroom home, but that can be knocked back by making it smaller – no bad thing when you realise the average New Zealand new home size is now the second largest in the world behind Australia.
The payback time is 5.5 years from lower energy and
“You’d notice. There’s a hell of a difference between 4 and 6”
Leigh Featherstone, Homestar director
water costs and lower maintenance.
“Six is easily achievable. There are builders producing 7s and 8s, but then you have to get a bit exotic about the water, such as reticulating greywater for flushing the toilet,” Featherstone says.
It’s not just for new builds. The majority of visitors to the Homestar website are people looking for renovation advice.
It recently launched a new subscription service – MyHomestar – to help people better understand how their new or existing home is likely to perform.
An online self-assessment tool allows them to assess their energy, health and comfort, water, and waste situation, rates the house from 0 to 10, and gives recommendations on home improvement and maintenance.
The subscription can give them access to special discounts from Homestar product partners such as Resene, Pink Batts, Cavalier Bremworth, GIB, Parex, Bosch, Showerdome, Earthwool and Placemakers.
“Homestar doesn’t recommend products. We give advice, and put products in a format that lets people make their own decisions,” Featherstone says.
It’s is pitched as a source of independent advice for those planning a renovation or purchasing a new house.
While other countries have introduced similar sustainability measurement systems, such as the UK Code for Sustainable Homes, Australia’s NABERS-Homes and Germany’s PassivHaus, Homestar is unique as it is applicable to both existing and new home builds including stand-alone, terrace and apartments.
As well as the consumer website (homestar.org.nz), there is now a national network of Homestar professionals to give advice, including Homestar Assessors that can certify homes.
Featherstone says Homestar is starting to be adopted by group builders such as Stonewood and Mike Greer Homes in Christchurch.
The organisation is also working with Otago University about a proposed warrant of fitness for rental properties.
He says with more than a million underperforming houses in New Zealand, there is huge scope for improvement.
The format of the Homestar tool allows homeowners to identify and prioritise what they need to do.
“No one fixes everything at once.”
Main picture: the average drafty Kiwi villa scores a two on the Homestar scale. Inset: this home in Nelson scored a six on the scale.