I was happy to see this lovely article on a very high-performance home down in Greymouth but I take issue with the last sentence, which implies that mechanical ventilation is needed because this house is special. Yes, this home requires mechanical ventilation … but so do all homes in New Zealand that have windows you can close. That’s been known …
Mechanical ventilation everywhere: not just high-performance buildings
Well-built high-performance buildings need mechanical ventilation. Times have changed, nobody’s really arguing about this any more. But all the other homes built in the last 50 years need mechanical ventilation also—those that only just met the Building Code minimum standards of their day. They’re not airtight (many of them are horribly draughty) but they still need proper ventilation. How do …
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 …
About time: Damn right, mechanical ventilation is appropriate in all new buildings
Why am I sounding overjoyed at this simple text from BRANZ? The backstory goes a long way back. In its <December 2019 Guideline https://www.branz.co.nz/guideline>, the front story is about smart vapour retarders (SVR) and how they lower the risk of mould in New Zealand wall assemblies. (There’s a story about that too, but that’s for another time.) The big …
Ventilation strategies
There are only a few actions individuals can take to improve indoor air quality (IAQ) in their own homes and the buildings where they work, learn or socialise. New Zealand buildings are typically not designed for 100% fresh air ventilation at sufficient rates. The long-term solution is to increase both expectations and regulations: every building should have continuous mechanical ventilation. …
Mechnical ventilation is a no-brainer
Fresh air is good for people but also the buildings I grumble about BRANZ, but the scientists working there are good people trying to fix problems with how we build. Unfortunately they are hamstrung by needing to do that while not changing how we build. That’s pretty much impossible. How about instead we just fix the Building Code? Proper …
More ventilation options now available
The percentage of New Zealand homes with visible mould is appalling—around half. The NZ Building Code has no requirements for ventilation in residential homes other than windows that are capable of being opened. This is manifestly inadequate*. Previously, I’ve pointed out that continuous extract ventilation is the cheapest functional ventilation option for New Zealand homes. It’s only the best option …
Cheapest functional ventilation option for NZ homes
When folks ask me what they should do first to their home, should they insulate the walls or the roof, or put in new windows, they’re surprised when the first thing I say is put ventilation in the building. Ventilation is extraordinarily important to your health, good sleep, and productivity. It removes excess moisture and CO2, and dilutes volatile organic …
Thermal bypass a basic step to improving building performance
I get asked periodically how to increase building performance without spending extra money. Well, better-than-Code performance is going to cost something so I focus on low-hanging fruit: what’s the greatest benefit for the least cost? Let’s assume continuous mechanical ventilation is already included, because that’s the single most important thing. After that, I recommend preventing thermal bypass via a dedicated …