It’s been 9 months since the Durbins moved into New Zealand’s most sustainable house and they haven't paid a single energy bill since.
Now the family don’t think they could ever move into a home built to standard construction methods again.
Living energy bill free
Their ‘Ideal House’ located in Beachlands, Auckland, generates substantially more energy than it uses and is the first Positive Energy home to have Passive House* Certification in the country (*PH, an accreditation of energy efficiency developed in Germany and spreading around the world).
Murray Durbin says they haven't had to pay any power bills and are self-sufficient for their water supply, but do have wastewater charges.
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“The money we would normally be spending on services can be re-invested in servicing the larger mortgage needed to build the home.”
He says the home has been sitting between 20-23 degrees Celsius through the colder months with no additional heating sources. It's kept warm by recycling all the energy naturally given off by the appliances, lights, hot showers, and body heat.
“The indoor air-quality is superb, and acoustically we're completely isolated from the world outside. It can be blowing a gale outside, and we're right under the flight path but we don't hear a thing.”
He says the biggest challenge of the build was getting their high Homestar rating around their waste management.
“We ended up doing most of the cleaning and sorting ourselves, and reduced the budgeted 6 skips down to 1 over the entire build by good planning, recycling, and re-homing. In hindsight we should have put either incentives or penalties in place with contractors to share this load.”
A few kinks to iron out
While spending all of their focus primarily on energy efficiency and sustainability, the father-of-2 says one area they neglected was the internal acoustics of the house.
“We have all hard surfaces (bamboo flooring, roller blinds not curtains, and limited furnishings) and we now have to add some treatments inside to address this issue.”
He says one of the other factors with high performance homes is their tendency to over-heat in summer, rather than getting too cool in winter.
“It's quite a different school of thought to Passive Solar Design, which once the heat is in your home, it can be very hard to control. There is no way of turning a large warm thermal mass (i.e. polished concrete floor) off when you don't want it.
“We did a lot of modelling for shading, and unwanted solar gain, and we got this 95% right - however there are a couple of windows which will now need some further shading from the hot western sun in summer.”
Inspiring the youngsters
Regardless of the minor tweaks being amended, youngsters, Tyler (8) and Annabelle (4) love their new home.
“Tyler has claimed to want to be an architect when he grows up, and all the pictures of houses he draws has solar panels on the roof, and plant rooms with ventilation systems as default. Quite different to the houses I used to draw as a kid, which always had smoke billowing out of a chimney on the roof. That's 'old school' now,” Murray says.
His passion for sustainable living is 2-fold.
“Firstly there's the health of our family. Being able to raise our children in a warm, dry, and healthy environment is paramount. Secondly, we're showcasing this build to encourage others to build beyond the Code. I see the Code as the minimum standard you can build a house, and legally get away with it. For 10-20% more than a traditional build, you can get something vastly superior, which will be healthy and save money not just for the first owners, but for generations to come.”
The future normal?
He believes if we lower our expectations around size, and lift our expectations of performance, it’s possible to build all of our homes to this quality.
“By cutting 20% off the floor area, you can reinvest the savings into better design and materials,” he says.” Covenants in green fields building sites, requiring 200m2 plus homes on expensive land are stretching people too thin and are road-blocks to allowing more high quality builds to happen.”
SEE ALSO: The real cost of building new
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