Leaky Buildings Syndrome



Syndrome: a combination of phenomena seen in association.


The Leaky Buildings Syndrome is the a name commonly given to the phenomenon of many, mostly residential, buildings built in the 1990s, leaking and rotting and being extremely difficult to repair, causing great economic loss to their owners and the community  and sparking much finger-pointing in the search for people to blame, and creating a whole industry of report writers, building experts and lawyers who have grown fat on the resultant litigations without really solving the actual problem. 


It would be impossible, in a short article, to exhaustively canvass all the reasons why the so-called leaky building syndrome occurred.  The following is therefore an essentially personal view.




The spirit of financial de-regulation which pervaded New Zealand in the 1980s, and generated considerable (short-term) wealth was carried through into the building industry.


The real cost of air transport having dropped, people were able to enjoy international travel to European destination such Italy and Greece and many came back with an admiration for plastered brick or stucco houses built without eaves found in such locales and sought to replicate these in New Zealand timber framed construction, forgetting about our rainfall and winds.


The 1990 New Zealand Building Code allowed and even encouraged alternative building systems.  Among those that gained popularity were monolith cladding system which included plaster-over-polystyrene wall cladding systems and fibre-cement cladding systems with or without texture coating systemss.  These systems, often improperly applied, were not completely water-proof and allowed water to enter, but sufficiently moisture-proof to stop moisture from escaping easily.  Thus, unlike in traditional weatherboard houses, the moisture was trapped.


For various reasons, timber merchants started to offer timber framing that was not treated with chemicals against rot.  They were able to do this after kiln-drying the timber and demonstrating that if kept dry but untreated, the timber would not rot.  Untreated timber held some attraction among those who were against unnecessary dangerous chemicals in the environment particularly in close proximity to people.


Deregulation extended into areas of public administration such as Building Controls.  Private building certifiers were permitted to approve, inspect and certify building works alongside the traditional Territorial Authorities such City Councils.


“Cowboy” builders without any formal qualifications, training or much experience were allowed to build houses and even larger structures. 


Important weather-tightness details, such as flashings, were omitted from many buildings.  The mastic gun became the weapon of choice for such builders.  It was not unknown for aluminium joinery to be sealed against the house by a single line of mastic applied on the four flanges of the window and pressed against the cladding and held in place by screws.


In due course, such buildings started to leak.  Because of the cladding system, moisture getting into the wall cavity was trapped. Often there was not enough moisture to get inside the house to warn the occupier but there was enough to start the untreated timber rotting.


Eventually, after many cases came to light, the extent of the problem became apparent.  Cladding could be replaced (with difficulty) but the rotting framing could not.


City Councils were reluctant to become involved, especially where they had not been responsible for inspecting the houses.  Any liability would eventually become a cost on their rate-payers. 


However when the problem became apparent, the Professional Indemnity insurers to the private building certifiers withdrew their cover at the earliest opportunity. Without PI insurance cover, the private certifiers folded their tents and disappeared from the market.  It was felt that any effort to pursue them for negligence would be largely fruitless.


Building contractors who, for whatever reasons, felt that they might be held liable for the loss arising from leaky buildings, liquidated their original building companies. Many then transferred their business to a new company and continued to trade but leaving owners with little recourse.


Typically designers, architects and engineers had little resources to fall back on and a single claim, if sustained, would exhaust their insurance.


Unfortunately, the last entities standing, typically including the City Council, are sued for the alleged total loss regardless of its true liability.


The alleged total loss includes not only the cost of the remedial work but also the cost of the investigations, reporting, expert witnesses, meetings and legal costs of both sides.  Because of the adversarial and winner-take-all nature of the process, both sides need to engage the best and most expensive experts to support their case. At the same time, the remedial work specified  and priced is often the most bullet-proof and gold-plated job possible – what you would specify if a barrister were at your elbow.


The Christchurch earthquakes being a disaster of even greater magnitude has diverted attention away from the leaky building syndrome.   Currently there is a proposal from the government for the City Council and the owner to each assume a proportion of the liability and for the Government to assist with funding.  However owners who feel they have a good case and someone to sue may decide to reject this offer and take the chances in court.


Currently because of the Leaky Building Syndrome, the likelihood of leaking is assessed using a Risk Matrix.  Building which “achieve” a high enough score are required to be built using “cavity construction.”   This is essentially a double-skin outer wall system with the outer skin held off the inner skin by vertical battens allowing any water to drain and fall out.  Current regulations also require window and other openings, corners etc to be extensively flashed and drained.  

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