New Zealand’s building industry has yielded some stunning results – from creative architectural typology in the residential sector, to industrial construction that pushes the envelope.

Unequivocally, there are compelling results to be celebrated and that have set a high benchmark.

But like many facets of life, the good often comes with the not-so-flattering reality of what can happen when standards are not what they should be or are blatantly ignored.

New Zealand’s news media headlines – while often sensationalised by nature – have lifted the lid on some uncomfortable and accurate truths about where the building and construction industry has fallen short on one of the most fundamental necessities in the sector – weathertightness.

We have all heard of the significant losses that come as a consequence of leaky homes.

This saga is a hangover from negligence in the 1990s and 2000s and has been an ongoing headache for the building sector, government, and affected residents, with many buildings compromised as a result

of lack of weathertightness, leading to unhealthy built environments and decaying homes.

Looking back at the catalyst for this particular crisis, there are many triggers.

One factor in particular was that the New Zealand Standard for Timber Treatment was changed in 1995, though was not cited in the Building Code until 1998, leading to a general acceptance of Untreated Timber for domestic house building.

This change allowed the utilisation of untreated timber for wall framing. When this timber became wet, it started to rot, and due to the introduction of increased insulation during this time, the moisture that came into contact with the untreated timber was slower to evaporate.

Cheap Monolithic cladding was also approved at this juncture, but was not always used within its specifications or installed correctly, leading to more mayhem.

Weathertightness expert, Chartered and Registered Building Surveyor Trevor Jones of Maynard Marks Limited warns, “Regarding weathertightness, not dealing with the causes of leaking is like a ticking time bomb”.

The New Zealand Institute of Building Surveyors member also adds that global events have shone a spotlight on other aspects of New Zealand construction, such as fireproofing and structural engineering.

“The thing to remember though, is that if you
make a mistake in one- unit design, and that
is then repeated 1,000 times, this can cause significant problems.
Good planning and robust design are paramount”

Maynard Marks building surveyor Trevor Jones

The fires at Grenfell Tower in London and Torch Tower in Dubai, which have drawn disturbing parallels, have triggered more checks and balances in New Zealand.

Trevor says these experiences, and the critical learning derived from them must
be heeded, and the prevailing issues in
the New Zealand industry addressed. “Memories can be short and people start to push the boundaries using new materials.

“There is also a drive right now with KiwiBuild using prefab; the idea is that things built in a factory setting are able to meet higher standards because arguably you have greater quality control.

“The thing to remember though, is that if you make a mistake in one-unit design, and that is then repeated 1,000 times, this can cause significant problems. Good planning and robust design are paramount.”

Trevor also expresses concern about the infiltration of offshore pseudo-materials that aren’t up to scratch.

He maintains that substitution materials in the construction arena can spell trouble, and that the advice by architectects and designers on which particular products

to use should be respected by builders, rather than going down a road less travelled and using alternative products with questionable integrity.

For those who own a leaky home in New Zealand, they have options to resolve these issues under the Weathertight Homes Resolution Services Act of 2006, which will be covered in the second instalment of this story. Keep an eye out for the Builders & Contractors 116 issue.

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