Estimating energy-efficient HVAC system costs for New Zealand homes

I’m often asked what an energy-efficient, low-emissions HVAC system actually costs to install here in New Zealand. The short answer is: we don’t have enough local data. But looking at...

by Jason Quinn

Updated: Apr 2026

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Managing moisture in mass timber: Please don’t leave it in the rain

Mass timber buildings are popping up everywhere in New Zealand and Australia, and for good reason. Substituting concrete and steel with Cross-Laminated Timber (CLT) saves on embodied carbon and offers...

by Jason Quinn

Updated: Apr 2026

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How long do our houses actually last? The 90-year reality

Retrofitting for performance only makes sense financially, at least when you’re already renewing a building element. Ripping off perfectly good cladding to add insulation is a tough sell, but doing...

by Jason Quinn

Updated: Mar 2026

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EnerPHit vs the ‘lite’ alternatives

I’ve been deep in the weeds working on the Deep Energy Retrofit Guide for New Zealand, and naturally, that means looking overseas for data we simply don’t have here yet....

by Jason Quinn

Updated: Feb 2026

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Short stays in Passive House homes in Aotearoa New Zealand

I’ve been describing the features and benefits of Passive House buildings for years but even my best words can’t convey as much as directly experiencing it with all your senses....

by Jason Quinn

Updated: Jan 2026

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What is “drier”? Relative versus absolute humidity in Auckland

I’ve just finished reading a new paper in the Journal of the Royal Society of New Zealand by Rochelle Ade, Mike Rehm, and Vishnupriya: “What is drier? Understanding humidity in...

by Jason Quinn

Updated: Mar 2026

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Burning stuff indoors is a $12 billion health bill

In our Passive House design and certification work, we often push clients to ditch gas hobs and wood stoves. Usually, we talk about airtightness, energy efficiency, and the fact that...

by Jason Quinn

Updated: Jan 2026

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Building science déjà vu: why we keep rotting our homes

In old homes we had (and have still in those not retrofitted) lots of energy flowing through the building elements: walls roofs and floors. This was due to lack of...

by Jason Quinn

Updated: Jan 2026

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A masterclass in detail: visiting a Japanese Certified Passive House

One of the best perks of working in this community is the people you meet. I first bumped into Miwa Mori at our very first PHINZ conference back in 2015....

by Jason Quinn

Updated: Jan 2026

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98% failure rate: The UK’s retrofit warning

A new report from the UK’s National Audit Office (NAO) dropped recently,  and the numbers are frankly terrifying. “Under the Energy Company Obligation (ECO) scheme, 98% of homes retrofitted with external...

by Jason Quinn

Updated: Jan 2026

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Sharing the Sun: Why high performance is essential for a fair grid

I was super thrilled when Philippa Howden-Chapman invited me to contribute to a new book, Sharing the Sun: Empowering small-scale renewable generation in Aotearoa. Edited by Helen Viggers, Keriata Stuart, and...

by Jason Quinn

Updated: Jan 2026

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Streamlining certification for multi-building projects

If you are working on a project with multiple thermal envelopes—even if they are just separated by breezeways—you need to remember the ground rules. Separate thermal envelopes imply separate PHPPs,...

by Jason Quinn

Updated: Jan 2026

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High performance airtightness costs no extra carbon

I wanted to point out a recent LinkedIn post by Sally Godber from WARM in the UK. I know Sally from discussions at a few Passive House conferences; she is a straight...

by Jason Quinn

Updated: Jan 2026

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EVs add to winter energy demand peaks

New research is a sharp reminder that if New Zealand wants a stable, affordable, 100% renewable grid, reducing demand is just as critical as increasing supply. The choices we make—about...

by Jason Quinn

Updated: Jan 2026

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How much is healthy indoor air worth? This study has an answer

The energy savings offered by building to the Passive House standard are easy to quantify. The comfort and healthiness of these homes is very much felt by those living in...

by Jason Quinn

Updated: Mar 2026

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PHINZ hui 2025: a summary and ideas for next year

What did you enjoy most? Well, talking to mates about Passive House is always my favourite. The Pecha kucha thing though! My expectations were low, I’m not familiar with the...

by Jason Quinn

Updated: Jan 2026

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Energy performance certificates for NZ homes

Talk of mandatory energy performance certificates (EPC) for New Zealand homes is always guaranteed to spark a lively debate. I admit to still being a bit on the fence on...

by Jason Quinn

Updated: Mar 2026

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Ara collab spreads Passive House influence

Ara Institute of Canterbury, a leading provider of construction training in the region, was the location for Sustainable Engineering’s last in-person certified Passive House tradesperson course. It was a great...

by Jason Quinn

Updated: Jan 2026

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