I estimate nearly half the thermal bridge calculations we see during pre-construction review are wrong. Newly minted Passive House designers and consultants are not wholly responsible. The Sustainable Engineering Ltd team is finding errors in the maths provided by experienced designers too. Lifting skills and confidence in thermal bridge modelling—and slashing that error percentage—is our motivation for organising an online …
Q&A: Is spray foam insulation a good idea?
Q. What’s your opinion about spray foam insulation for New Zealand homes? A. Spray foam can be used with good results if properly designed and installed well—but a successful outcome requires both of these or a lot of luck. In the UK, there have been enough problems with bad installations of spray foam in retrofitted roof insulation that it impacts …
MBIE releases technical guidance on operational carbon
I welcome the release of technical guidance for operational carbon calculations by MBIE, as part of its Building for Climate Change programme. There is lots of work ahead of us but it’s an important step to have a document to argue about now. In short, the methodology calculates energy use by predictive energy modelling and uses a badness factor (annual …
New thermal bridge requirements in US will influence NZ
There are new thermal bridging requirements being rolled out in the US, of which ASHRAE has just summarised. ASHRAE standard 90.1 is for all new buildings excepting low rise housing and the 20220 version introducees many changes to improve energy efficiency. Fun (?) fact: there are many thousands of different Building Codes across the US. However, 90.1-2022 is a core …
SEL validates ECCHO tool to international standard
Energy modelling New Zealand homes at design stage is easier and more widely available, thanks to a project by Sustainable Engineering for the New Zealand Green Building Council (NZGBC). ECCHO has been accredited under ASHRAE 140, a confirmation that ECCHO’s calculations are correct. This work was carried out by SEL principal, Jason Quinn. ECCHO had to be validated in order …
Your clients must own the risk that goes with cost-cutting
How is risk allocated in the design of new buildings? Who benefits and who pays for it? This is at the crux of some very interesting conversations I’ve been having recently with designers and engineers on multiple projects. Sustainable Engineering has recommended particular solutions that carry almost no-risk. Yet the client doesn’t want to pay for best practice solutions and …
The slow switch to ISO standards in NZBC
New Zealand is slowly switching over to using ISO standards, at least for our building energy work and code in H1. The revised H1 switches to the following standards, so far: ISO10211, ISO10077-1/2 ISO13370 I expect that someday we will replace NZS4214 with ISO6946. I also suggest we explore adopting ISO standards under the “The Energy Performance of Buildings Directive …
Least cost, most benefit from jumping straight to Passive House performance
Something I learned from my dad growing up was to do something right … so you only had to do it once. When you do a half-arsed job, you often have to do it over again. I was reminded of this when Jonathan Holmes (VIA Architects) recently pointed out a great technical paper from the UK. It dates back from …
How Luggate Memorial Centre got made
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 …