Siân Taylor of Team Green Architects, Marc Lithgow of Space Division, and Tim Ross of Architype design passive houses, and all three live in one. Federico Monsalve spoke to them about comfort, cost, where the movement
is headed, and why the idea hasn’t yet tipped here.
Homestar, eco house, carbon zero, straw bale, and just plain green; sustainable housing has never been short of labels. One, however, has stood the test of time in terms of functionality and liveability, and continues to gain adherents in the westerner world.
In brief, Passive House is a performance standard rather than a style: continuous insulation, an airtight envelope, high-performance windows, the removal of thermal bridges, and mechanical ventilation with heat recovery work in tandem so that a house holds a steady, comfortable temperature with very little heating or cooling all year round.
The movement began in Germany in the late 1980s, when physicist Wolfgang Feist and Swedish academic Bo Adamson set out to define a house efficient enough to do almost without a conventional heating system, even in the most bitter European winters. Their prototype, a terrace of four homes in Darmstadt-Kranichstein, was completed in the early 1990s. Thirty years ago, Wolfgang founded the Passivhaus Institut (PHI) to formalise, test, and certify the criteria that would come to define a movement.
It wasn’t, however, until 2012 that Australasia’s first fully certified Passive House began to rise — in Glendowie, Auckland. Its owner had commissioned a conventional family home from Jessop Architects before discovering the standard, and the details had to be reworked to meet it.
Much of the story now reads as an early-adopter’s struggle. Consent stalled because council staff were unfamiliar with the technology, and it took the intervention of Auckland’s then urban design champion, Ludo Campbell-Reid, to move things along. With no local certifier, it was assessed from Ireland. The ventilation unit came by ship from Europe, the window profiles came from Germany (a practice that continued for many years), and the inward-opening tilt-and-turn joinery had to be proven to council.
Passive housing made sense locally. In a country that promotes itself as clean and green, with a tradition of trying to tread lightly on the land and a te ao Māori world-view grounded in kaitiakitanga, the movement has gained slow, but steady momentum. In early 2025, it was estimated that nearly 200 fully certified houses existed, although the number is likely to be higher.
Now, nearly 15 years on from that first step, more people have taken up the challenge, architects among them. Marc Lithgow of Space Division moved into his own passive house (final certification pending) in May of this year, and set out to test an argument.
“I did try to dispel myths,” he says. “I’m using 100 by 50 framing. That’s not very exciting, but I was trying to prove that, in the more benign Auckland climate, the only thing you were really doing differently was the airtightness layer.”
In layman’s terms, the architect was trying to prove that the Passive House framing, which is usually 140mm to 300mm thick to accommodate the various insulation layers, did not have to be so thick to still accomplish passive performance.
The windows, too, show how far things have moved since Glendowie. Marc uses Optimal Windows, made in New Zealand rather than Germany.
“[The owner] brings in the locking mechanisms, but the rest of it he’s making here. The timber’s from here. He’s putting them together in his workshop in Kerikeri, and they’re glazed here, too. So it does remove an element of complexity around [importing] the whole [thing] from Germany, which is certainly what we did for our very first job.”
Siân Taylor of Team Green Architects, whose home is outside Arrowtown, says that the most obvious lesson people need to learn when designing passive houses is simplification.
“It saves money, makes it inherently more energy efficient, more durable, because you haven’t got as many junctions and materials, so less carbon. Everything about it is better if it’s simple.”
What she values most became clear during a night at a new Auckland hotel.
“I was thinking that would have been a perfect passive building,” she says, “It’s just a simple box, essentially, with windows; it’s not loads of glass … But essentially, it’s still a typical New Zealand building,” — making the connection between the simplicity of good, formalist design and strong passive ethos.
At home, she says, “We just leave the house — holidays, days, nights — and come back, and it’s exactly the same. My [husband] talks about freedom all the time. You never think about being cold. You never think: ‘How [am I] going to heat it?’ You never worry: ‘Am I leaving the heating on?’”
Tim Ross of Architype, agrees.
“Every time I see new builds, it just feels like a missed opportunity, because it’s really not that difficult, unless you’re trying to do something really complex with the form … I’m five years in, and I still wake up and I’m like: ‘Man, this is wild. We haven’t had the heater on in weeks, it’s snowing outside [in Dunedin], and we are walking around in T-shirts.’”
So, passive builds are, indeed, achieving such great levels of comfort in the extremes of Dunedin and Queenstown, what is stopping them from becoming commonplace across the country?
For Siân, it is perception.
“There’s this misconception that it’s way harder than it is, and that it’s going to change the architecture … people think it’s going to be a design compromise.”
Tim identifies two barriers.
“The first is a lack of appreciation about how good it is, because really it’s something you have to experience first hand. Then, probably, an overestimation of how complicated it is.” Cost, he adds, is largely a matter of experience.
“When you’ve got a team which has been doing them regularly, cost starts to come down a lot. It’s the learning and making mistakes which can be more costly.”
Marc puts it more bluntly. “It’s about comfort, and most people don’t really understand the numbers. They don’t mean anything until you exist in it.”
And it is true; the marketing of these abodes can often be riddled with blower test hocus pocus that doesn’t truly give an indication of their liveability.
Timing matters, too. Tim is often called by owners hoping to upgrade a house already under way.
“Much of the time, unfortunately, it’s too late … It really needs to be solved on the drawing board.”
Siân sees the same missed chances at the design stage.
“The most obvious one is simplification … Everything about it is better if it’s simple. But it’s just a mind switch, isn’t it, to simplify?”
Elsewhere, uptake has been rapid.
“In Ireland [and Scotland], for instance, there are thousands of passive houses completed or under construction,” says Tim.
His statement is reinforced by the Passive House Association of Ireland, which stated “Certified units rose from 340 in 2024 to 1129 in 2025, reflecting growing confidence in high-performance building as a practical, scalable solution for Ireland’s housing and climate goals.”
What was the catalyst?
“Often it’ll be some small thing, like a slight tweak in the regulations, that all of a sudden makes it cost neutral,” continues Tim.
In Australia, he notes, green financing from banks has “made a huge difference.”
Siân points to Scotland, where a citizens’ climate assembly led to legislation.
“When governments realise that, that’s the big moment … It’s a tipping point, but … it’s definitely not happened here.”
Tim believes the grid argument is undersold.
“On the coldest winter day, when most buildings are demanding their peak, these passive buildings demand next to nothing.”
Yet he sees no political champion currently fighting the cause.
“I think it’s pretty much up to industry at the moment to lead in the absence of leadership from the government.”
His case for acting anyway is practical.
“I think we’re going to see winter electricity become more expensive, with data centres and things like that … So I think it’s a great way to futureproof your home against the developments in electricity costs we’re likely to see.”
Three questions for Rafe Maclean
Wānaka architect Rafe Maclean lived with his family in the Kōwhai House, a Certified Passive House (CPH) in Dunedin, until 2025, when they moved back to Wānaka, where he is about to start building a new CPH.
What were you most proud of at Kōwhai House?
The incredible comfort levels, and very low power bills. It’s a healthy environment, too — most of my family are sensitive to allergies, and two members had severe asthma issues before moving in. Since then, the asthma has faded away thanks to the filtered air and humidity control, which prevents internal mould issues. There’s also a better sleeping environment, with constant fresh air and low CO2 levels in all rooms.
And I love good architecture, of course — to blend and incorporate Passive House thermal modelling as a design tool during the design stage, setting up a predictable performance result while expressing strong architectural gestures — that is our, as a practice, sweet spot.
Knowing all you know now since you built this house, what would you do differently?
We are currently designing our second CPH, so this is a relevant question. With this new house design, we’ve worked on optimising the detailing, so we’re doing more with less and keeping it simpler — but making sure there are still strong architectural [features], interesting shapes, and satisfying details that will uplift our daily lives.
What do you think would help improve uptake of passive houses locally?
Stronger legislation from central government on building performance — a poor building built now is the next generation’s liability. Generally, [we should] treat buildings as infrastructure, not a commodity — this would change the conversation dramatically, about quality and cost benefits over time. And bold developments — using CPH architects to design low-cost housing more. We can make large gains in building performance and comfort levels with little material change.
