A new Kāinga Ora development will allow residents to heat their homes for just $1 a day, as climate change encourages a new generation of energy-efficient housing.
The Building Code is 20 years behind other OECD countries and allows us to design and build “the worst buildings we are legally allowed to build”, according to high performance building architects, designers, and manufacturers.
Not waiting for the code to catch up, two things are helping them to leapfrog it now to build future homes for future generations.
First is a steady increase in demand from clients. These clients are often returning ex-pats who have lived in homes overseas built to higher performance building codes and are specifying those standards for their own, says Warm Windows operations manager Junior Chile.
“We started this business for 16 years ago, but we only started to see consumer change in the last five years – mainly from expats returning from Europe and North America where these windows have been standard for a long time,” says Chile. “Kiwis coming home know the benefits of these windows which have a 50 percent better thermal performance than standard windows.”
The second driver is volume from large scale high performance home developments such as Kainga Ora’s (formerly Housing New Zealand) Passive House community housing pilot in Māngere called Bader Ventura after the two streets it borders.
The project has recently received design endorsement to build to the Passive House standard which was developed in Germany and is now adopted in more than 66 countries around the world.
Certified Passive Home building standards delivers a comfortable, well-ventilated home that needs very little energy to heat or cool and is now the mandatory building code in countries such as Scandinavia and Switzerland.
However, according to the Passive House Institute, there are just 56 certified Passive House projects in New Zealand – a tiny amount compared to the some 40,000 building consents issued annually for homes built to the current New Zealand Building Code.
“The current Building Code allows the worst buildings legally allowed to be built. It’s inadequate and not going to push along innovation.”
– Shaun McIsaac, Oculus
A lack of awareness of Passive House benefits and higher building costs, perceived or real are still two of the barriers stopping more being built but that is changing, says Shaun McIsaac, a director of passive house engineers Oculus, working on Bader Ventura.
“Three years ago, designing and building high performance homes cost a 30 percent premium – now it’s three to five percent with the volumes we are seeing,” reveals McIsaac.
“The current Building Code allows the worst buildings legally allowed to be built. It’s inadequate and not going to push along innovation. At Oculus, we are designing and building long beyond it and are not waiting for the building code to change.”
“The Building Code says materials should last 50 years – but why not 100 years or more? Using material that has longevity creates far better economic value for the building over time.”
– Justin Bragg, Concretec
As a pilot project for Kāinga Ora, the three-storey, 18-home Bader Ventura development in Māngere is the first major milestone for the organisation to produce a certified passive house which can be heated for as little as $1 per day.
Kāinga Ora construction general manager Patrick Dougherty, says the development, when complete, will be a win for both the environment and the homes’ new occupants. It’s a big step towards meeting the Ministry for Business proposed final thermal performance cap 12 years ahead of industry expectations, he says.
Bader Ventura, and hopefully other high performance home projects commissioned by Kāinga Ora, are good news for suppliers such as Concretec which are manufacturing the structural pre-cast concrete panels for the outside façade walls. The three layers in the panels provide structure, thermal mass, and insulation, says Concretec director, Justin Bragg.
It’s the first time the product has been used in social housing, says Bragg. “It is usually used in high-end houses as it’s a little bit more expensive. But for a small percentage increase in cost, it delivers a huge percentage improvement across so many other areas for its longevity, low maintenance, thermal properties – and the other big need of the building industry – speed of installation.”
Kāinga Ora projects like Bader Ventura have given Concretec the ability to step up its process-added ability in pre-fabrication. It can deliver panels onsite with all exteriors finished and even with the windows installed.
“It’s a big step forward and quite rewarding to be involved with these projects that fit with the government building for climate change and provide materials for the harsher weather we might get in the future.
“The Building Code says materials should last 50 years – but why not 100 years or more? Using material that has longevity creates far better economic value for the building over time.”
The price of impassivity
The cost of not building dry, warm, healthy homes can be easily measured in our rate of respiratory illness and associated healthcare.
According to the Asthma Foundation, one in six of us have a respiratory disease, one in seven children have asthma, respiratory diseases are the third most common cause of death – and these diseases have a $7 billion healthcare cost to the country each year.
What mirrors these statistics with startling similarity is Statistics NZ’s Housing in Aotearoa report in 2020 stating:
• Dampness and mould are common in New Zealand homes. Around one in five homes are damp sometimes, and one in six have patches of mould larger than A4 size.
• One in five New Zealanders live in a home that is always or often too cold in winter, and this rises to around two in five Pacific peoples.
So, are our homes slowly killing us? According to certified passive house designer Catherine Ford, “the current code falls short by a long shot”.
“We assume that new homes will be warm, and healthy, but there are no minimum temperature standards for a New Zealand home nor measured energy performance in the Building Code,” reveals Ford, the director of Potential Architecture Limited, a Taranaki architectural design company specialising in healthy upgrades, energy modelled efficiency and sustainable design.
“Only old people’s homes and early childhood centres, have to be able to achieve minimum indoor temperatures, and not with any degree of consistency at all. The beautiful thing about the passive house method, is that you can choose the healthiest materials available.”
We can’t keep doing what we are doing, says Jon Iliffe, one of the founders of eHaus, a nationwide network of passive house designers and builders.
“By 2030 we are meant to be transiting to new building standards which could mean one of three things,” says Iliffe. “We maintain the status quo, there is a middle ground, and then there is building to passive house standards. Even the middle ground will be a significant step forward from where we are now.”
For the high performance home movement to really gain momentum in New Zealand requires the scale of projects like Bader Ventura to raise awareness of the benefits as well as lower the cost of materials and fittings, says Passive House Institute chief executive Amy Tankard.
“In the UK and Canada, there are social housing Passive House projects being built on a large scale which are achieving the same price builds as normal homes,” says Amy.
“Living in a warm, dry, high air quality home has a huge impact on health and mental wellbeing.”
– Amy Tankard, Passive House Institute
Iliffe agrees and says China picked up using passive House systems four years ago and is now building whole towns because of the energy savings and health benefits.
“We are advocating that building passive homes should be mainstream,” says Tankard. “It’s a rigorous and measurable design and build system. From the plans, we can plug in the data to see how your house will perform to proven standards anywhere in the country. Living in a warm, dry, high air quality home has a huge impact on health and mental wellbeing.”
The Ministry of Business and Innovation consults every year on the Building Code. It provides an opportunity for the public and the building and construction sector to have their say on proposed changes aimed “to make homes and buildings warmer, drier and healthier, with less impact on our environment, while also bringing New Zealand more in line with international standards”.
The Ministry has reviewed this year’s extensive public submissions and says it received more submissions than in the past five years combined. Out of the 711 submissions, by far the largest number (684) were on energy efficiency for housing and small buildings. (Read more here)
Ministry officials are drafting the 2021 update to the Building Code based on this feedback and it is expected to be published in November 2021. Until then, keep on wheezing.
