Why Passive House costs more

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 …

Healthy Homes Standard tweaked

A December 3 announcement on changes to the Healthy Homes Standard solves one of the issues caused by this well intentioned legislation. We were designing absolutely best practice apartments, which wouldn’t meet the HHS extract requirements for ventilation. I discussed this with HUD several times and I can vouch that their people wanted to encourage this best practice—but they were …

New thermal performance data for NZ timber window profiles

Consulting with building component manufacturers to help them make good products even better is a favourite activity for the Sustainable Engineering team. Lunds Joinery, a highly-regarded family-owned company in Timaru, approached us to do some window calculations for their standard timber profiles.  Lunds incorporated the fRSI calculations and Uf data into a new publication, the LJT Timber Window Guide, which …

Loopholes in H1 changes?

To be clear folks: H1/AS1 housing changes apply to all housing, even huge retirement communities and apartment buildings of any size. BPI (Building Performance Index) is no longer a permitted compliance method. Curtain walls are included in the R-value requirements (no change) per either H1/AS1 or H1/AS2—but need to be calculated by ISO12631. Lots of folks seem to be focused …

NZ “outsulation” guide now available

Now available: the Outsulation Guide for High Performance Walls, brought to you by Outright, suppliers of continuous insulation. Sustainable Engineering provided the thermal modelling calculations and I enjoyed the discussions we’ve had about applications. This guide focuses on external insulation (“outsulation”, get it?) of walls with a focus on residential applications. Download a free copy here. I’ve been asked to …

Energy efficiency will improve

Today we have it: the new H1 has been released. I no longer need to keep it all secret and can finally talk about the new energy efficiency requirements. Note there is a year’s lag before these come into effect (“adjustment period”). Just get on with it, I say to the heel-draggers. As MBIE says, “the changes go as far …

Airtight building resources

Here’s an excellent resource on planning, training, mocking-up and doing QA on an airtight building project. It’s very graphical and has great links to even more resources.  There’s video as well for those who like moving pictures. Haven’t heard of ZEBx? No surprises, it comes out of Vancouver, that northern beacon of best practice for zero-emission and high-performance building. In …

Homestar V5 a huge improvement

The just-released Homestar V5 tool is going to lift the performance of homes using the NZ Green Building Council (NZGBC) rating system because the PHPP software is now the engine under the hood. We’re super-excited, just as you’d expect from building science geeks! We’re also a bit proud, because the Sustainable Engineering team was involved in developing the improved tool. …

Generic slab edges default should be B’/2=2m

A slab edge is one of the most common thermal bridges we see in New Zealand. In a traditional timber framed building on a concrete slab, the perimeter thermal bridge will often have a large impact. “ISO13370: Thermal performance of buildings — Heat transfer via the ground — Calculation methods” provides the steps to calculate it and take into account …