
UPDATE: It’s confirmed, Little Greenie is the first HERS 9 star rated home in New Zealand.
Christian Hoerning from the from the Energy Efficiency and Conservation Authority tells it like he sees it:
The house received a Home Energy Rating (HERS) rating to independently verify the standard of the house’s energy efficiency. HERS is a scheme that we at EECA run. The house achieved a 9 star HERS rating which is only one step away from being a zero energy house (the rating scale is between 1-10). This is likely the highest rating a house in NZ has received to date – we are verifying this today but it looks highly likely.
A few other points to note:
- While this is not a low-cost design, it’s not luxurious either and is therefore achievable for many New Zealanders today.
- The house has been designed to achieve good aesthetics, great comfort, very high energy and environmental performance and minimal maintenance requirements at reasonable building and minimal running costs.
- The annual heating demand is about 85% lower than for an average new build built to code minimum requirements, and about 97% lower than for an uninsulated house in the area.
- The owner is very happy to talk about the HERS rating publicly and welcomes any publicity.
The owner has also installed many data loggers to monitor the actual energy performance and proof that it works – this will be evaluated by the School of Architecture of Victoria University of Wellington.
As this example demonstrates, international best-practice, highly energy efficient and future-proof Kiwi home design is already achievable using products and techniques which are readily available in New Zealand and do not need to cost an arm and a leg.
As this house is a holiday house this is an opportunity for other New Zealanders who consider building to visit this house and experience the comfort of ultra-low energy houses.
The Home Energy Rating Scheme is an invaluable tool which assists New Zealanders with making informed decisions for achieving energy efficient home designs.
The key points which helped achieving such a highly energy efficient house are:
- Compact, simple building layout
- Good solar orientation of windows
- Super insulated roof, walls and floor – more than twice as much insulation as required by the building code.
- The thermally best performing double-glazed windows available in NZ have been used.
- Thermal mass in the concrete floor and adobe walls collects the sun’s warmth on sunny days and release it overnight and on cloudy days.
- Solar water heating for hot water and underfloor heating.
- Attention to detail in the design.