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 …

Join US expert on marketing PH to homeowners

I’m looking forward to this seminar on how to effectively market Passive House and encourage those working on and designing Passive Houses to attend. This Zoom seminar is hosted by the Passive House Academy New Zealand on 29 June 2021 at 11am. It features John Oppermann, a US real estate agent (and executive director of the Earth Day Initiative), who …

HPCD summaries released by BRANZ

If you haven’t already reviewed the technical draft of our High-Performance Construction Details (HPCD) Handbook, BRANZ has just published two great summaries that pull out the high-performance wall and roof assemblies (elements). The wall elements from the HPCD Handbook are summarised with the results reproduced in BU660 Residential walls with high thermal performance. The roof elements from the HPCD Handbook …

Does what it says on the tin

A study in the UK of 97 certified Passive House projects shows predicted heating demand was accurate in both flats and houses. Measurements were recorded for over a year of both heating demand and internal temperature. Results:  average measured heating demand 10.8 kWh/m2/year predicted heating demand 11.7 kWh/m2/year.  The study’s authors considered this statistically identical. Several of the buildings in …

Toward net-zero building: put this paper on your reading list

Advances Toward a Net-Zero Global Building Sector is a BIG tech paper, happily published with open access so people outside of academic institutions can actually read it. See below for the abstract and a link to the paper. New Zealand is well represented in the paper’s database due to our Passive House buildings. The following items are worth paying particular …

Retrofit alert: know when fire-rated components are called for

Fire rating of the building/windows is not something we usually need to worry about in new, detached single-family homes, as the clearance to the property boundaries is sufficient. But during retrofits—especially ones that involve a change of use—fire regulations can have a big impact. It’s best to avoid the need for fire-rated windows as they are big money and poor …

Local MVHR only 40% efficient, says BRANZ test

We go to great lengths to maintain the certified level of MVHR efficiency in the high-performance building projects we consult on. We recommend or specify cross-counter flow heat exchangers with well insulated boxes, short exterior air ducts (also well insulated) and semi-rigid or rigid distribution ducting inside the thermal envelope; with all that, projects often achieve 80-90% overall efficiency (ie …