Christchurch house joins ranks of top Homestar homes

22 April 2016

A second home at Christchurch’s Church Square has achieved the highest Homestar rating possible – 10 Homestar Built – for sustainability and energy efficiency, thanks in part to its compact, smart design and a high-performance thermal envelope.

The single-storey home, located at 9 Church Square, Addington, is the second home in the country to achieve the Built rating. It received the rating in February and is being launched today as a showhome, to coincide with Earth Day. It sits next door to the first home to achieve a 10 Homestar Built rating, and both were designed by Christchurch architectural designer Bob Burnett. (A Papamoa, Tauranga home was the first to achieve the 10 Homestar Design rating last year.)

Launched in 2010, Homestar is the independent system that rates the health, efficiency and sustainability of New Zealand homes on a scale of 1-10. It assesses energy, water, waste, ventilation, health and comfort, and other environmental factors, at Design and Built stage, and is certified by the New Zealand Green Building Council (NZGBC).

The three-bedroom home has a footprint of 154sqm (including a 36sqm carport), which is smaller than most other three-bedroom houses – so fewer resources are used to build the home. A GIBFIX framing system significantly reduces the amount of timber used and allows room for more insulation. The edges of the house’s concrete floor slab are insulated, there’s a ducted energy recovery ventilation system, and innovative hydronic underfloor heating also keeps the home comfortable.

10 Star Homes CEO Dr Greg Chawynski says it’s a myth that building healthier, more energy-efficient homes is too expensive.

“We’ve shown we can build a home with no net power bills by using technology, good orientation for sun and excellent levels of insulation. These methods are within the reach of anyone building a house today, and they make homes healthy, comfortable and cheaper to run,” he says. “Achieving a 10 Homestar rating means we also have independent assurance of the home’s strong sustainability credentials, making it a desirable long-term investment too.”

NZGBC CEO Alex Cutler says the home is an excellent example of how making good choices at design stage quickly shows benefits, and this principle applies right across the country.

“Homestar recognises that building a slightly smaller home reduces the resources you use and the overall build cost, meaning you can invest extra money in things like insulation. And when cooler weather settles in, which will you be happier to have – an extra bathroom or a warmer home?” says Ms Cutler. “Sustainability is an integral aspect of healthy, affordable housing, and we’re delighted to see another high-performing Christchurch home demonstrating what’s possible.”

Other features of the house include:

  • A solar-powered electric-car charging port, which is free for the public to use while the home is being used as a showhome
  • PV solar power and energy-efficient lighting and electrics, including surface-mounted LED lights to avoid breaks in ceiling insulation
  • External wall frames are least 140mm thick and have a chemical-free Rigid Air Barrier (RAB), which provides resistance to wind and earthquake loads that far exceeds Building Code requirements
  • Combined rain-water and grey water system, and water-efficient fittings
  • Low-VOC paints and sealants, and other materials are certified by Environmental Choice NZ or Forest Stewardship Council
  • Built to a 5 Star Lifemark rating, the highest possible rating certifying accessibility and adaptability for occupants of all ages.

The Homestar Assessor was Julie Villard of Bob Burnett Architecture.