Ever told a client that they could save 200 kWh/m²/year in heating for their 180 m² home? That’s a normal statement from a Passive House designer looking into a deep retrofit option. Do you know how crazy that sounds? Seriously, even with a COP of 3 heat pump, that’s 12,000 kWh/year of heating electricity (200*180/3) or roughly $3,600 annually just …
Energy-efficient homes sell for (a lot) more
The Domain Sustainability in Property 2025 report is a data-rich look at the value of energy-efficient homes in Australia. It shows, in no uncertain terms, that buyers are not just interested in sustainability—they are actively paying a significant premium for it. For years, I’ve been worried that professional valuers in New Zealand might not properly account for the superior performance …
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 …
Canada tackles the massive task of greening its buildings
We often look to other countries for examples and lessons learned in the push towards sustainable buildings. A recent article in Canada’s National Observer (July 2024) highlights the significant challenge and opportunity facing Canada in transforming its building industry to meet net-zero targets by 2050. The built environment, including construction, materials, and operations, accounts for nearly 30% of Canada’s greenhouse …
Heat Pump Hot Water Heaters: They Move Heat, So Think About Where That Cold Air Goes!
We’re seeing more and more folks making the smart switch to heat pump water heaters (HPWHs) to slash those energy bills – and rightly so, especially if you’re a hot water fiend. But a recent Insight from the legendary Dr. Joseph Lstiburek serves as a crucial reminder: these aren’t your grandma’s resistance element heaters. Think about it: heat pumps pump …