Rochelle Ade’s doctoral research findings have had quite a bit of media attention in recent weeks. Not surprising, given her claim that Homestar ratings aren’t delivering what they claim (and that the rating tool may be breaching the Fair Trading Act). Effectively, Ade measured the temperature and relative humidity of 30 homes in Auckland: those built according to the current …
Passivhaus In Australia book now available
If you haven’t yet downloaded and read the excellent book produced by APHA, Passivhaus in Australia, I highly recommend it. Although New Zealand had a head start over Australia on Passive House design and construction, the Aussies have now clearly surged to the lead with their large complex projects. School classrooms, student accommodation and a high-end apartment building have all …
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 …
Interior condensation should be expelled from school
If Leaky Buildings 1.0 was about rain getting in where it shouldn’t, then Leaky Buildings 2.0 is all about the build-up of condensation, such that it feels like it’s raining inside. Building physics knows how to build schools that stay dry inside. But here we have another school with a roof that drips on the kids inside due to interior …
BRANZ sees the light on mechanical ventilation
Holy sh*t. Talk about a big shift in perspective. Let’s repeat that: “BRANZ now recommends that residential buildings are mechanically ventilated and are built to an airtightness target.” This comes from an article in the Oct 2020 edition of Build magazine, available online. In it, Senior Building Performance Engineer Greg Overton says “the measurements [from their latest research] sit alongside …
Technical guidance for Formance SIP in Passive House projects
SIP manufacturer Formance has released a technical bulletin for designers focused on how to specify or calculate Formance panel performance for certified Passive House projects. The bulletin is based on a report by Sustainable Engineering. The values provided on the Formance website (for an overall wall assembly with air surface film resistance and cavities) can’t be directly entered into PHPP. …
Green co-leader backs Passive House and co-housing
Great to see Tim Ross of Architype guiding James Shaw around the building site of the Dunedin co-housing project. When this project is completed next year, it will (if it meets the certification standard) jump us up to over 50 Certified Passive House dwellings in New Zealand. If we can use this template to guide our social housing design and …
Understanding DataTables and Variants
Tech Tips with Toby Variants is a handy tool when using PHPP to model multiple design options within the one PHPP file. Suppose you’re trying different window frames, glazing or types of insulation: the variants tab is the place to do it. The Excel tool behind how that sheet works is called DataTables. To understand how the variants sheet works, …