New thermal performance data for NZ timber window profiles Lunds Joinery get ahead of the pack

13 December 2021 by Rachel Rose

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 has a real focus on thermal performance. These traditional JMF timber profiles perform well when installed to the JMF install. Use the form here to request a copy of their guide (the “information pack”).

The real benefit is twofold: the reduced thermal bridging around the frame due to the timber construction and the reduction in the installation thermal bridge (window-to-wall ) junction due to the JMF install.

Commissioning this work to understand exactly how their products perform puts the Lunds team in a really good position in relation to the Building Code updates just announced. They can prove they easily exceed the new R-values required by the changes to H1.

Timber frames naturally have a big head start on aluminium when it comes to performance. WIth the right type of glazing, these standard profiles may meet Passive House performance levels in warmer New Zealand climate zones.

SEL’s director, Jason Quinn, offered some advice about the best pathways to designing much higher-performing window frames and our team will follow the company’s direction with interest. Jason also built a R-value calculator for Lunds, which should prove its use in the developments ahead.

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