Kāinga Ora’s new Passive Home apartments should mean zero heating costs

Aere and Albert Ahsin of Māngere were flooded out of their Kāinga Ora home of 42 years in January. Their home wasn’t red-stickered, but the floodwaters went right through the house, and wrecked their car.

It was a bad start to the year, but things have just got a whole lot better – in a couple of weeks, the Cook Islands couple will be among the first tenants to move into New Zealand’s first certified Passive House social housing complex built to Homestar 8 status.

Bader Ventura is an 18-unit “pilot” just around the corner from their old home. Counting a stand-alone house on the site, there are 19 homes replacing the three old state houses that once sat on the land.

But what’s most special about the 18 apartment units – 12 of which are three-bedroom, and six are two-bedroom – is the fact they are exceptionally well insulated, airtight, and fully ventilated with an out-of-sight mechanical ventilation system.

Aere, 69, and Albert, 76, and an adult son who lives with them, are likely to spend just $1 a day on heating, averaged out for the year – money which is covered by the annual $350 subsidy given to beneficiaries and superannuitants, so the net cost to the couple will likely be almost zero.

The temperature inside their apartment will stay around 21deg to 25deg; the air will be fresh and filtered, and they, and the other families, are likely to stay in better health. The homes regulate the temperature through smart design, and the use of high-performing construction materials, so there will be little need for the family to run their space heaters, even during colder periods.

Aere and Albert say it took them a while to agree to a move after four decades – they had been shown other houses that they had refused. Then they were encouraged to come down and have a look at a three-bedroom, ground-floor apartment in Bader Ventura.

Once they saw it, they were overwhelmed. The apartment meets “universal design” criteria, so it is fully accessible, which is beneficial to Aere, who has mobility challenges. There are two bathrooms with a toilet in each. One bathroom is wheelchair accessible, and the other has a bath.

‘Like a million-dollar mansion’

“My husband said, ‘we have been blessed, my wife. We’ve been blessed by God’,” Aere says. “God has given us a new car [a gift from Aere’s sister], and now he has given us a new home. Take it!”

Albert says when he walked into the unit and saw how new and perfect everything was, his heart went out to the homeless, and those impacted by the floods in January. “It’s awesome. I cannot explain it any clearer. We are one of the lucky ones to move in here; it’s a once-in-a-lifetime opportunity to get into a brand new house. It looks like a million-dollar mansion. And we know it’s going to be warm.”

“It’s fantastic,” says Aere. “It’s warm, and it’s insulated. My husband said to me, ‘you’re getting old now; you’re nearly 70, and you can’t garden any more’, so the first thing I noticed was no more lawn. And no dust.”

Kitchens in each apartment are basic, with L-shaped benchtops, a traditional freestanding oven, pantry, and plenty of cupboards and drawers. There is no island, but there is room for a table that could also functional as a workstation.

Each unit has a covered balcony that can be used as an outdoor room, and there is screening to provide privacy from neighbours, while still allowing residents an outlook.

The Kaīnga Ora team gathered when Stuff visits includes family liaison staff helping Aere and Albert, and everyone is just as excited as the couple themselves.

Patrick Dougherty, Kāinga Ora general manager construction and innovation, says Bader Ventura is the first public housing building in Australasia built to certified Passive House standard.

“It’s very exciting. We’ve got a few bruises along the way trying to work out how to do it well, but that’s the key. It’s just finished, [so costings haven’t been finalised], but we are going to do a full analysis of the costs.”

Dougherty says similar sensors have been put in a new Kāinga Ora development over the road that is not a Passive House building, so they will be able to do a comparison.

‘Looking for a two-year commitment’

Angela Pearce, Kāinga Ora regional director says they are still in the process of choosing tenants for the apartments, and are focussing on customers already in their homes that have known health issues.

“We are quite interested in seeing the real benefits – what this home will provide for them. We make it really clear about all the sensors and monitors, and we’re quite keen to have all our customers really engaged about that.

“We are looking for people who are want to be part of this, and we are getting a lot of positive feedback. It is a two-year commitment – we would prefer they had plans to hang around for two years, so we can have continuity of information. That’s an ideal.”

‘Public houses’ are not pubs

The pair refer to their projects as “public houses”, not to be confused with pubs – it is simply a way to differentiate their social housing units from those provided by other entities, such as the Salvation Army.

For this public housing, health benefits are way up on the plus list. “People do struggle to consider a move, after many years in one of our homes,” Dougherty says. “We’ve seen many stories where families who live in what is considered a good home in Auckland, but have got asthma, and then they come into a home like this (a new build), and they stop going to the doctor. It’s just a remarkable shift.”

Pearce says: “It’s not uncommon to hear them say, ‘I no longer need to go to a doctor; I no longer have to go to emergency at Middlemore’. It’s a striking difference in what a warm and dry home can do. It’s just the smarter way these buildings are built. It’s remarkable, particularly for respiratory illnesses.”

Kāinga Ora has staff who work with the local community, helping people transition between homes, and working with them throughout their time in public housing.

Dougherty says many of their customers have things going on in their lives and other issues to worry about, “so there is a real basic need to have them satisfied in the way they are housed”.

“And the real cool thing about a passive house is that it’s passive. Often houses that have this degree of complexity can translate to being difficult to manage. But it’s quite the other way round.”

Each apartment has its own mechanical ventilation unit (above the ceiling) that automatically circulates the filtered, fresh air through the home. None of the systems is interconnected, so there is no mixing of the air from other apartments.

Importance of feedback

Brian Berg, Kāinga Ora carbon neutral housing manager says the monitoring and evaluation of the sensors won’t provide the only feedback on Bader Ventura. “We’ll be talking to the customers, and asking them how they’re really feeling about living in the space. It’s so important.That innovation, and partnering with Bader McKenzie [building] across the road, is going to pay off for us, and continue long term.

“So in many ways, although this project is almost finished, the scientist in me is really excited about the long-term, and the things in planning over the next couple of years. Do the benefits that we’ve calculated and engineered actually translate into reality for our customers in our homes?”

The real data to come from this will influence Kāinga Ora’s future designs, Dougherty says. “We’ve got an idea of what we think will happen, but the reality will unfold, and we’ll learn from it.”

Other sustainability features

The Bader Ventura apartments are built from precast low carbon concrete, which is considered excellent for airtightness and durability. The wall system is a sandwich panel, consisting of a structural layer, an insulation layer, and a cladding layer.

The cladding is a combination of two cement replacements – Fly Ash and Neocrete’s D5 Green, a natural pozzolan. This has reduced the cement in the wall panels by 24%, and the embodied carbon impact by 18%, compared to standard practice. the panels were constructed off-side, and the windows pre-installed.

The thermally broken uPVC window frames were imported from Germany and assembled in New Zealand after being tested in extreme conditions to ensure high UV stability, so they won’t warp or get brittle in the sun. They are double-glazed, which, combined with the mechanical ventilation, means there will be no condensation, and outside noise will be greatly reduced.

Air filters within the mechanical ventilation remove pollen and other allergens to ensure the whānau have clean, healthy air all year round.

Dougherty says the project will achieve MBIE’s draft Building for Climate Change 2035 ‘final’ thermal performance cap 12 years ahead of expectation.

Project partners:

• Architects: Peddlethorp
• Construction: Precision
• Passive House lead and facade engineers: Oculus Architectural Engineering
• Structural engineers: Kirk Roberts
• Building services engineers; 2PIR
• Passive House certifiers: Sustainable Engineering