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NZ Building Science – Kiwi Windows #NZBS 1

Welcome to the first of many articles on building science in New Zealand. If you know me well, I’ve been a practicing engineer in North America for the past 9 years and have recently moved to New Zealand to work with a leading (read: only) building science firm in Auckland. These articles are intended to give you a snap shot of the NZ building industry and some perspective on where it could (should) be in the near future.

Prior to moving to New Zealand, I was told by many that the NZ building technology was about 10-15 years behind North America. While a little difficult to comprehend what that meant or how it would impact my life, that very abstract idea hit me on day one.

I moved into a short term rental upon arrival in NZ. The home is a new home built in about 2010. Very modern, no shortage of high end finishes and on a nice piece of land. The home uses double pane IGU’s, pretty standard, but the frames are non-thermally broken aluminium. Thermally broken aluminum (typo for emphasis) has been a requirement since the early 2000’s in North American and now more modern frame technologies such as PVC and fibreglass dominate the US and Canadian markets. And yes, I double checked and these windows meet all the energy requirements of the NZ building code, R-0.26 (SI) or U-0.68 (IP).

Auckland is a mild climate, but overnight lows in the 5C (41 F) range means these frames cause some problems. Firstly, having done all that I can to control the humidity in our bedroom still results in puddles of condensation on the interior of the window frames every morning.

During this “cold snap” (overnight lows around 5C) our small plug-in space heater was put to the test barely managing to get to 18C (64F). The home relies on a combination of plug-in space heaters and a wood burning fireplace for heat, fairly common in NZ apparently. The bathroom has in-floor radiant heat (a modern luxury) but otherwise the most modern home on the block has a very simple, nostalgic, yet ineffective heating system.

Needless to say these cold nights have been a stark reminder of why I came to NZ and the tough work ahead.

All that being said, the city is absolutely beautiful and we’re settling in nicely.