Auckland enforces tougher leak rules

By ANDREW LAXON

All new leak-prone houses in the Auckland region are now required to use wall cavities and treated timber for protection against leaks and rot.

Other councils around the country are expected to follow Auckland's lead soon, rather than wait for a decision from the Government or the Building Industry Authority.

The combined changes are expected to cost about $1000 for an average house.

However councils predict the numbers of affected homes could be relatively small, as builders and architects are already going back to more traditional designs.

Auckland City Council principal building officer Bob de Leur said the stricter system had been in use for about six weeks by council inspectors and private building certifiers in Auckland, North Shore, Waitakere, Manukau, Rodney, Papakura and Franklin.

It applied to houses with a high risk of leaking and rotting. Risk factors included flat roofs, no eaves, parapets and balconies, seamless plaster finished walls (known as monolithic claddings), complex architecture (including multi-unit developments) and exposure to wind and rain.

Mr de Leur said these homes would be required to have a gap between the outside cladding and the timber framing, allowing water to drain away.

The buildings would also need to use treated timber - either H1 Plus (a boric treatment regarded by the Forest Research Institute as good short-term protection against rot) or more expensive H3 timber.

Mr de Leur admitted that six major cladding manufacturers had partly forced the councils' hand on the timber issue, by declaring in October that their guarantees might not apply unless their products were used with H1 Plus treated timber.

He said councils were already seeing a return to traditional, lower-risk building materials and design methods because of publicity about the leaky building crisis.

As a result, Auckland City Council, which handled 800 consents a week, had needed to intervene in only about one case a week since the new rules came in.

Mr de Leur said councils from around the country met in Rotorua three weeks ago to discuss implementing similar standards. Wellington and Kapiti Coast had already shown an interest in following the Auckland region's example.

The new council rules, whichare still being finalised, havepre-empted similar plans by theGovernment, in response to an inquiry led by former State Ser-vices Commissioner Don Hunn.

The Government is also considering compulsory registration and insurance for builders to protect homeowners.

The council moves are identical to those proposed by North Shore building surveyor Philip O'Sullivan in a letter to the Building Industry Authority two years ago.

At the time the authority's architect Claire Benge dismissed the cavity plan as "an unjustifiable increase in cost to the industry" and a return to treated timber as "a backward step".

The authority is now on the verge of introducing compulsory treated timber for outside walls and is considering compulsory use of cavities.

* If you have information about leaking buildings,
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Herald feature: Leaky buildings

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