There are lots of different reasons why people build Passive House homes And even in NZ, the cost premium is evaporating

11 April 2024 by Rachel Rose

What motivates people and organisations to build better homes? And how do they afford them? It was interesting to chat with Architype principal Tim Ross this week about the Arthur Street townhouse project (see the case study here). This home stands out for being built-to-rent. It’s in Dunedin, a climate badly in need of warm, dry housing. It also features a classic Dunedin site, a little wedge of a very steep street.

Architype already has experience in building multi-unit rental properties to the Passive House standard for both private and public landlords. We have the built proof that developers can make the numbers work in one of the colder climates in New Zealand. The further north one goes (leaving aside places of significant altitude), the easier it is to hit the certification targets. It’s good to know there are multi-unit developments in work currently in Auckland; I’ll look forward to sharing more details about those in due course. Having honed their craft in the chilly south, Architype designers find themselves pleasantly surprised by what they can get away with on Auckland builds, for instance. 

Affording performance

Uninformed chatter persists about the additional cost of building high-performance homes and it creates unfortunate confusion. Tim Ross has a spiel for potential clients wondering if they can afford Passive House and interestingly, it starts with the cost of windows. They are the hardest part, he says. If the project can accommodate that cost and the site isn’t too shady, his team is confident they can make Passive House numbers work. In chilly, damp Dunedin.

Other costs net out: for instance the money saved by deleting full underfloor heating can go to the cost of the MVHR system. And while a Passive House building typically has lots of extra insulation (in Dunedin at least), that cost is not significant in the context of the overall build.

 

Tim posted to LinkedIn recently about a large Passive House social housing project he visited, under construction in Zaragoza, Spain. It’s a project from Grupo Lobe, a private builder/developer that has built over 2000 certified Passive House apartments, with thousands more underway. It’s well worth a read. Key takeaways are the importance of scale and integration between design and construction. Also that by their nature, apartments are the low-hanging fruit for cost effective high-performance! Grupo Lobe is delivering certified Passive House performance at the same price as an equivalent building that only meets legal minimum standards.

(I particularly liked Tim’s subsequent comment: “I came away really positive about the difference that integrated design can make. I saw hundreds of small innovations in the building design and construction process which cumulatively made this level of performance very achievable … I think lateral thinking, removing complexity and communication between builders and designers are key.”)

Motivations

It’s made me reflect on the increasing diversity of what motivates people and organisations to build to higher performance standards than building codes dictate. I’ve been talking to Passive House homeowners, designers, architects and builders for the past six years. For early adopters looking to build their own home, it was usually about their comfort and health. More recently, environmental concerns have come to the forefront, with a lot of discussion about operational carbon emissions. But on an individual level it can be as simple as liking new tech and wanting a durable, quality asset. It’s something for the Passive House community to keep in mind: there’s not just a single story to tell when it comes to encouraging Passive House takeup.

As Grupo Lobe shows, private companies can drive a power of good, ahead of regulatory requirements. If Kāinga Ora’s ability to keep forging on with Passive House level social housing is constrained by new political realities, New Zealand will have no choice but to look to the private sector to keep up momentum. Fletcher’s LowCO housing is a bright spot we’ll continue to follow with interest. It isn’t certified Passive House but it turns out to be really close to the certification targets. More on that next month.

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