Leaky building syndrome FAQs

The leaky buildings issue has had a profound impact on New Zealand and its people, particularly those who own or live in a leaking home. But what exactly is leaky building syndrome? What causes it, and perhaps most importantly, what can you do about it when it affects you personally?

The following guide answers common questions about leaky buildings, and will help you decide what to do next if you are the owner of a leaky home.

What is leaky building syndrome?

Leaky building syndrome occurs when the design or construction of a building does not provide adequate water tightness. While the ingress of water is not necessarily a problem for all buildings, certain types of building design and construction allow water to penetrate, but not to escape or dry out. In these buildings, moisture levels rise and rot forms, eventually weakening the structure of the building and causing health hazards.

Some of the tell-tale signs of leaky building syndrome are:

  • High moisture readings
  • Bubbles in coatings caused by water penetration behind plaster
  • Saturated cladding causing moisture to soak into bottom plates

Experienced building surveyors agree the highest risk of leaky building syndrome is in the homes built between 1987 and 2004. According to the Weathertight Homes Resolution Service (WHRS) the construction peak for leaky homes was in 1999/2000, mostly in multi-unit developments.

What causes leaky building syndrome?

Leaky building issues started in the early 1990s, with the trend towards Mediterranean-style homes. Previous building practises in New Zealand used more traditional building styles with timber weatherboard cladding and joinery. While these leaked a little, they were also ventilated so any moisture that entered the cladding system naturally dried out.

The new style of Mediterranean homes often used ‘monolithic cladding systems’ such as plaster on polythene or cement sheeting, which were frequently used or applied incorrectly. The use of plaster systems over a timber substrate resulted in the plaster cracking and allowing water to pass into the cladding system, but not allowing it to dry out, as the plaster systems were reasonably air tight. 

This, combined with issues in the design and construction of buildings, contributed to the leaky building problem.

Then, in 1998, the NZ government and the Building Industry Authority (BIA) approved the use of untreated, kiln dried timber in construction. This only served to compound the problem, because it allowed rot to develop even more freely in buildings with inherent design and construction problems.

In summary, the main causes of leaky homes are:

  • Modern cladding systems being used outside their specifications or installed incorrectly.
  • Inadequate construction of certain design features that do not allow for deflection or drainage of water.
  • Insufficient testing and subsequent application of new products and methods.
  • Lack of technical knowledge and skills when houses are designed, detailed and built.
  • Use of un-treated kiln-dried timber framing more susceptible to rot.
  • Air-tight sealing of claddings and windows and wall cavities filled batt insulation.

How can leaky building syndrome be avoided or prevented?

To prevent leaking, it is imperative for new buildings to incorporate the ‘4 D’s’ in their design and construction:

  • Deflection: Keeping rain away from moisture-sensitive areas with the use of correct detaining and the proper use of flashings and eaves.
  • Drainage:  Providing paths for water that gets behind cladding to drain away. Drained cavities are one example of this.
  • Drying: Providing ventilation to spaces that would otherwise trap moisture, so that the moisture can escape and not cause rot.
  • Durability: Specifying materials in areas such as roofs and walls to a suitable level for the situation and environment.

How many homes are affected by leaky building syndrome?

A report issued in July 2009 by Pricewaterhouse Coopers estimates there could be up to 89,000 homes affected by leaky building syndrome. Only 3,500 have been fixed so far, and it is estimated that a further 9,000 are outside of the 10-year limitation period for legal liability.

As of 30 November 2009, the Department of Building and Housing had received 5916 claims lodged for 7581 properties and completed assessments for 7470 properties.

British Columbia in Canada faced exactly the same issues from 1987 to 1997, with about the same number of dwellings affected.

What’s the cost of leaking homes in NZ?

The leaky buildings disaster is expected to cost the government $1 billion over the next 5 years, but only to fix some of the damaged homes. The government estimates that 70% of affected homeowners within the 10-year liability limit will take up the government assistance they are entitled to.

But the cost of leaking homes isn’t just limited to financial damage – the health costs are also potentially substantial. Dampness in walls and floors creates an environment for the growth of toxic varieties of mould, such as stachbotrys and fusarium, which can be very harmful to health.

What help is available to owners of leaking homes?

Under the new financial assistance package offered by the New Zealand Government, owners of qualifying leaking homes may be entitled to a 50% contribution to the costs of repairs. The contributions are broken down as follows:

  • Central government will contribute 25% toward repair costs.
  • Local authorities will contribute a further 25% of the cost. (Note: Not all territorial authorities are participating in the FAP scheme.)
  • Affected homeowners will contribute the remaining 50% or 75%.

To be eligible to claim, the WHRS Act 2006 requires the following

  • The dwelling/house was built within 10 years immediately before the day of the claim is filed and before 1 January 2012.
  • Water has penetrated the dwelling/house.
  • The dwelling/house was damaged as a result of the penetration of water. 

Unit owners have to pay any contribution to weathertight remediation or repairs that their body corporate legitimately demands of them, but mortgagees or lenders are not responsible for contributing to weathertightness-related costs.

It’s also important to be aware that owners who use the scheme relinquish their rights to take legal action against local authorities and government.

What should I do if I think I have a leaking home?

If you own a leaky building, it’s important to do something about it as soon as possible, to avoid any further deterioration in the structure of the building, and to minimise any health risks. 

If you suspect your building could be at risk of leaky building syndrome, or you already know your home is leaking, you also need to act fast to ensure you get the help you’re entitled to under the WHRS scheme.

Many of our clients have used Resolution Architecture as their first port of call when they suspect their home is leaking. We can help you throughout the entire process, and recommend professional and reliable partners to assist with your solution. Contact us today to make an appointment or get advice on your situation.

How long will it take to fix my leaking home?

On average, re-cladding takes between 3 to 6 months, but Resolution Architecture will work with you to develop a solution that meets your schedule, and your unique needs. Just contact us today for a no-obligation appointment to discuss your situation.