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 this issue. But the study I discuss below does recommend most of what I’d like to see included, should such a programme be introduced to Aotearoa. Two things are controversial: …
That’s not Passivhaus, that’s just expensive
Years ago I warned of what I dubbed cargo-cult architecture, where architects throw in a few high-performance components like expensive windows and lots of insulation and expect a high-performance building to magically result. It’s a recipe for disaster and particularly risks creating houses that are unbearably hot in summer. This approach is based on guesswork and magical thinking, not building science. …
As-built tests for thermal performance of building envelopes
Of course I’m going to love a presentation that included differential equations! Fellow engineers Cameron Munro (Passive Analytics) and Harley Truong (Logikhaus) put their heads together shortly before the conference to envisage what form a new as-built measure for the performance of a building’s thermal envelope might take—the equivalent of a blower door test for testing airtightness. This is a …
Energy-efficient homes sell for (a lot) more
UPDATE [11 July 2024] This post, first published on 13 June, has been edited. See the addition under the Methodology heading below. We’re not putting too much weight on its claims now we have looked at the methodology involved. For years, I’ve been worried that professional valuers in New Zealand might not properly account for the superior performance of a …
Stay dry: how to prevent moisture-related problems in construction
This half-day workshop is offered on 30 July 2025, immediately prior to the PHINZ hui in Christchurch. It’s designed for architects, Passive House designers and tradespeople and its practical focus will equip people with the knowledge they need to safely design and build building envelopes—from Building Code-minimum to high-performance. Condensation and mould are not just problems in tired, old housing …
The underlay dilemma: getting it right under your metal roof
When it comes to constructing or renovating a roof with metal cladding in New Zealand, one crucial component often overlooked until problems arise is the underlay. An awesome overview document from metal roofing manufacturers (published in 2011) titled “The Underlay Dilemma” highlights the critical role underlays play in the long-term performance and durability of your roof. I especially loved the …
Air sealing with sealant and backing rod: yes, you need both
When it comes to keeping our buildings weathertight and preventing unwanted airflow, the humble air seal plays a vital role. The duo of sealant and backing rod are one option to achieving this around windows and doors. But how do they work together, and why bother with both? One of the primary reasons we meticulously install an air seal is …
The path to decarbonisation for the aged care sector
EECA, the Energy Efficiency and Conservation Authority, launched a valuable resource in 2023 to support the aged care and retirement living sector on its decarbonisation journey. The suite of tools and resources, developed with input from the sector, aims to help reduce emissions across the sector. We’ve worked with several retirement community providers in the past and I wish these …
Understanding Our Energy Use: The RBS as a Foundation
When we talk about how much energy our homes in Australia and New Zealand consume, chances are the data underpinning those discussions comes from the Residential Baseline Study (RBS). As highlighted in the recent methodology report for the 2021 update (RBS2.0), this study is a bottom-up engineering, end-use energy model of our residential sectors. Essentially, it builds up a picture …