New houses have cladding and joinery that lasts just 15 years

Friday, 19 July 2019

Modern houses are built to last 50 years, compared with crafted hardwood villas which last more than 100 years.

Modern homes have a much shorter lifespan than many of their owners appreciate, construction law expert Tanya Wood says.

New home owners have little idea that construction materials such as cladding and windows are only required to last for 15 years, Wood says.

Builders, designers and developers are grappling with planned changes to the Building Act over the lifespan of materials, builder qualifications, and liability when things go wrong.

Wood says the construction scene is an 'industry of disputes', based on cases she has dealt with in the courts about building materials and the way they were installed.

'When I commute to work and see all the new subdivisions on my way, I ask myself how many homeowners know they might be facing re-cladding and other replacements within 15 years.

* Changes proposed to Building Act mean tougher consequences for failings

* Builders may have to upskill to meet higher standards under the overhaul of the Building Act**

Leaky building lawyer Tanya Wood says building rules about the durability of materials fall below what most people expect.

'Compare modern homes with the materials and craftsmanship of a 100-year old villa – the modern home is built to last 50 years.'

Wood says that in her experience, cladding and window joinery often don't meet even their required 15-year longevity, sometimes because of quality, and installation.

Wood says standard aluminium joinery companies mostly provide a five-year warranty.

But if window joinery fails and has to be replaced it often requires removal of the exterior cladding too.

A plywood-based cladding material called Shadowclad has been the subject of court disputes for more than five years. Complainants say it is not fit for purpose.

The 2015 manufacturer's specifications say that when Shadowclad is used in dry interiors it will meet 50-year durability.

When used for exterior cladding, the specifications say Shadowclad meets 15-year durability requirements under the Building Code, and painting is recommended.

Regardless of Shadowclad issues, Wood says homes are still being built in ways that led to the leaky building crisis.

House building relies on skills of tradesmen, architects, engineers and designers but Wood says there is a race to the bottom when tendering for work at lowest prices. And there is often a lack of oversight by councils.

'Some designers don't understand the building process, and architects often don't understand how buildable their designs are.

'When a dwelling is being constructed it needs to be done in sequence, before the next stage. Designers need to understand the sequences because builders want to get on the with job as quickly as possible.'

High material costs, lack of supplier competition, and council compliance expenses shave profit margins, so the builder need smooth building processes, Wood says.

Some proposed changes to the Building Act seem aimed at reducing liabilities of councils, such as capping their liability to 20 per cent in the event of a claim, she says.

Wood also questions a proposed change to compulsory insurance to cover defective work because it is unclear if the insurance industry is prepared to provide cover.

Even if they agree, costs are likely to be higher and will be passed on to consumers, Wood says.

Home Owners and Buyers Association (Hobanz) chief executive Roger Levie describes the 50-year house compliance lifespan as 'crazy'.

'Old villas are built with better craftsmanship, harder wood, and better ventilation even if that makes them a bit cooler. While you expect to do regular maintenance there aren't systemic problems,' Levie says.

Modern houses are built to last 50-year lifespan, much shorter than for older timber buildings.

'Problems arise with monolithic construction where the framing is softer pine, sometimes untreated and then enclosed with a plaster so there is less air circulation.'

The problem is especially acute in Auckland's humid climate, causing insulation to slump against framing and causing rot, Levie says.

'It's going on inside peoples' homes and they have no idea.

'The fact cladding is only required to have a 15-year life span is absurd. Consumers don't understand that is all that's required under the law.

'It creates conflicts because if you want to take legal action you must do it within 10 years. If a building material has a 15-year lifespan and fails after 12 years you can't seek redress.

A 100-year old villa has generally been crafted with more durable materials.

'It's a perverse negative incentive for manufacturers who only need to get to the 10-year legal limitation period.'

Levie says the act also allows some non-structural repairs to be completed without resource consent.

'Buildings may be re-clad without consent on the basis the material has reached its 15-year life span.'

But removing cladding might reveal rot in the structural elements underneath that requires building consent to fix it, and sometimes builders go ahead with the re-cladding anyway.

Such work is illegal and can result in challenges when the house is sold, Levie says.

'We want to see the Building Act explain the requirements more clearly,' he says.

Registered Master Builders Association chief executive David Kelly says it is unreasonable to expect consumers to research and understand benefits of various products.

'Consumers need to be able to rely on professionals such as architects and builders.

'Builders do have an obligation to fix things but if they have left the industry or gone broke or moved overseas there's no one to go back to and that's when warranties and insurance come in.

'A home is usually someone's biggest investment so if they decide they can't afford some kind of protection they're taking on a big risk, Kelly says.

Master Builders contracts offer 10-year guarantees covering workmanship and about three years for materials.

The Building Code clause stipulates the required lifespan off all the building components. For example, fire-rated internal and external doors have the same 15-year life requirement as ordinary doors. Wiring behind linings has a 15-year rating, but 50 years if it is within concrete slabs.

Registered Master Builders Association chief executive David Kelly says building professionals must take the lead in choosing durable materials.

Discussion documents on the Ministry for Business Innovation and Employment web site include a survey of homeowners' and builders' attitudes.

The homeowners range from people who fully trusted their designers and builders, to those who actively oversaw each step of a new building or renovation.

In most cases even those who took an active role were unclear about where responsibility lay, how they could resolve disputes, and the significance of a written contract.

Builders also had widely differing perceptions of the risk they faced.

Some felt that if they did a good job they would have nothing to worry about.

Others believed a contract placed them at more risk. One group of builders simply avoided work they thought might involve risks.

Builders were usually prepared to fix things for the sake of keeping clients happy, and for their reputations, even if a defect wasn't their fault.

Larger established companies seeking a professional image recognised that risks were part of running a business.

These 'do it by the book' builders were also open to educating clients about consumer protections to help mitigate risk, and saw benefits for themselves in doing so.

The Property Council, representing commercial property owners, wants the Building Act to make it clear that manufacturers, architects and engineers, rather than suppliers like Bunnings and Placemakers, are most responsible for ensuring a product is fit for purpose.

The Property Council says that using proposed phrases such as 'intended to be used' is open to interpretation and future legal disputes.

The proposed changes to the Building Act and the submissions by interested parties are expected to result in Government decisions by the end of this year.