Overheating kills and it can kill quickly. The number of days where temperatures climb over 25°C is projected to increase between 40% and 100% by 2040 in New Zealand. Overheating is an especially significant risk for vulnerable groups like children, the elderly and those with pre-existing health conditions. It’s much harder to ensure a building stays cool in summer compared

It’s hard to feel optimistic about the likelihood of bold change to address climate change and human health, welfare and equity right now. But from a technical perspective, it makes sense to take aim at the root of the problem of New Zealand’s in general poorly performing, unhealthy buildings and change the Building Code itself. I had to gloss over

Fast, cheap, good: pick two. Everyone in construction has heard that saying. But it’s challenged by the prefab building manufacturer Manor Build’s achievement of a volumetric 6 Homestar version 5 (v5) rating for three different home designs. A volumetric rating is a bit like pre-approval for a mortgage. Any home built to these designs, in any of the North Island

Trickle vents are making a comeback in New Zealand because in combination with small extract fans they are the lowest-cost way to meet Homestar v5 requirements for continuous ventilation. However trickle vents are not ideal. It’s possible to specify additional small components to improve how this combination functions and it will succeed in reducing relative humidity and introducing fresh air.

Hygrothermal modelling may be more familiar to you as WUFI, the acronym for the software used to carry out the analysis. Don’t be intimidated by either name. Stick with me as I explain what it is, why it’s important and when you should consider seeking out this modelling. Like energy modelling at design stage, the basic premise is simple: experiment

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

Here’s a good summary on make up air for rangehoods, from HVAC consultants and designers at Energy Vanguard. It’s worth reading in full. The quick summary goes like this: Good kitchen cooktop installs position the cooking hood against a wall, and it fully covers the cooktop. In such a case, 125 L/s or 425 m3/hr is sufficient for a normal

We’re having some robust conversations about MVHR specification and installation as more homes seek Passive House certification and some designers focus on keeping costs as low as possible.  It’s an interesting time right now because we have more data and anecdotal insights. The rate of design and construction of Passive House projects is on a steep upward trajectory in Aotearoa

This project is the first government-owned social housing in Australasia to earn Passive House certification. Its success is down to the vision and determination of some key individuals, chief among them the project manager at Kainga Ora and those who supported her bold bid to radically improve the performance of these apartments.  Bader Ventura is well ahead of Kainga Ora’s

New Zealand’s first Passive House community facility—and it stands in a tiny rural community of a few hundred people. How did this bold project get made by a small council at the furthest end of the motu? Sustainable Engineering talked to the people involved in the rebuild of the Luggate Memorial Hall, seeking insights that might help other non-residential projects

Architype in Dunedin has notched up another Passive House win, with successful certification of the country’s first social housing units. Our case study notes the challenges that were met with regard to budget and design time and how the designers drew on what they’d learned working on Toiroa High Street, Dunedin’s cohousing development and first multi-occupancy Passive House project in

Sustainable Engineering’s team is involved, as consultants, designers or certifiers, on virtually every Passive House project in New Zealand (plus some in Australia and projects that head toward but don’t make the final grade for Passive House certification). Given that breadth of involvement, I feel confident to make some predictions for 2023. Celebrating 2022’s achievements There are lots of firsts

Great to see Fletcher Living’s announcement about its Low Carbon initiative. The Sustainable Engineering team has really enjoyed working with Fletcher Living’s people on their vision for low carbon homes that meet the 1.5 degree Celsius carbon budget. Exploring the operational energy and the embodied carbon impacts of many practical, more affordable housing options has been super enjoyable. Fletcher Living

The long-awaited first Emissions Reduction Plan was published yesterday and media commentators are rushing to dissect it. I liked that the foreword describes the problem as also an opportunity: “a challenge present[ing] the single greatest opportunity we’ve had in at least a generation … It means warmer homes and lower household power bills.” I have three initial observations, specifically on

Update 16May2024 We want folks to know that Kainga Ora has regretfully informed us that they are now in the process of officially closing the R&D component of the project as the investment is no longer commercially viable. They are removing their pages from their website and links to this will no longer work. Kāinga Ora’s ambitious research project, Ngā

Living in a cold house you can’t afford to heat causes physical health problems, up to and including premature death. There’s plenty of evidence supporting this and I’m grateful to researchers like Professor Philippa Howden-Chapman and her colleagues at the University of Otago for (a) doing the research in this country and (b) communicating their research findings to a broad

If you’ve met Christchurch Passive House builder Peter Bielski, you’ll know he’s a man of few and well-chosen words, not minced. His company is involved in an ambitious project to create a new sub-division of certified Passive House Plus homes. In a recent blog post, he tackles the question of cost premiums for Passive House performance. He’s quite right: when

We have it at last: as of 29 November 2021, New Zealand has a new energy efficiency code clause (section H1 of the New Zealand Building Code). Don’t be fooled by the 11 month waiver: the changes have already come into effect. The waiver allows the use of old materials and designs for a year (and sadly means some parts