BRANZ’s position on the Building (Overseas Building Products, Standards, and Certification Schemes) Amendment Bill has been clear throughout the consultation. It has been grounded in ensuring that building products, regardless of origin, are fit for purpose in the Aotearoa context.
And when it comes to understanding what ‘fit for purpose’ means in terms of our climate and New Zealand Building Code compliance, BRANZ has an arsenal of scientific data upon which to draw.
How different is different?
New Zealand’s unique environmental conditions – high UV, geothermal activity, earthquake frequency and climate change-induced risks such as flooding – are well documented. But how different are we really from other nations?
What BRANZ can prove is that New Zealand is really, really different. With more than 25 material testing and outdoor exposure sites nationwide, BRANZ has been collecting data since 1973. That data shows us how materials will withstand the elements for generations to come, ensuring the sector uses products with proven performance qualities. The objective is to avoid poor decisions that result in potential failures or costly fixes.
Similarly, understanding if a product is fit for purpose in the context of New Zealand building methods is also key. For example, plasterboard is used as a structural element here, unlike in many other countries.
What the Chatham Islands tells us
I might not be the biggest Neil Young fan, but he was right about one thing ... rust never sleeps. As our BRANZ scientists pore over the results from our outdoor exposure sites, he could have added ‘especially in the Chatham Islands’.
With an unforgiving climate – howling, salt-laden winds, high UV, constant moisture and temperature swings – the Chatham Islands’ corrosion rates far exceed the harshest coastal sites in New Zealand and Europe. The findings are graphic. Just one example: an unprotected 1 mm carbon steel plate that lasts more than 50 years in inland rural areas of New Zealand disintegrates within 1 year. Further, the rate at which carbon steel corrodes in the Chathams is 22 times faster than inland New Zealand and nearly double the highest corrosion rate recorded at marine sites in Europe.
Why is this important? After all, the Chatham Islands are more than 800 kilometres away with a population of just 600 people. Aside from it being essential for building resilience on the Chathams, as climate change-induced weather changes intensify, the Chathams’ experience could be the rest of New Zealand’s experience in 50 years’ time.
The Chatham Islands materials testing sites are a crystal ball, a glimpse of New Zealand’s potential future. Importantly, the data can be used to model the impacts of projected climate change on the New Zealand mainland and future-proof buildings today.
Build it once, build it right, build it affordably
BRANZ welcomes the government’s commitment to tackling housing affordability by increasing access to international building products.
As the regulations supporting the new building product specifications pathway are being developed, BRANZ will continue to advocate for evidence-based assessments. Decisions must be grounded in scientific research, informed by real-world New Zealand building practice and align seamlessly with the New Zealand Building Code to ensure the highest standards are met.
We also believe it is crucial to recognise the interconnected nature of building regulations. The systems governing consenting, building products and resource management must all operate in unison if we are to deliver homes that are not only affordable but also resilient and durable.
With an unwavering commitment to quality assurance, our mantra must be to design it right, build it right and operate it right.