The Unconditional Blog

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The leaky home legacy becomes a global phenomenon

Posted on: February 22nd, 2011 | Filed in Architecture & Construction, Featured

New Zealand, as has been well documented is facing a legacy of building issues related to “leaky homes” – a legacy for which estimates vary, but seem to be around $11 billion according to a recent PWC survey, with potentially up to 89,000 properties effected. The fact is emerging though that this phenomena is not unique to NZ. The US is appearing to show the same cracks, metaphorically speaking, in their housing stock which equally could cost them many billions of dollars. Nor in fact was NZ the first country to suffer this damaging phenomena as housing in Vancouver was discovered to have suffered from leaky buildings way back in the mid 1990’s

In the US during the 5 years at the start of this millennium around 10 million new homes and apartments were added to the housing stock as reported in the recent headline article in Business Week. This boom in construction was fueled by the easy credit environment which went on to become the catalyst for the sub-prime meltdown and subsequent Global Financial Crisis. The scale of the US issue is not as yet estimated. All that is reported is that defects identified in properties built during this period are running at twice the rate of the prior 5 year period on a per property basis.

The roots of both countries construction issues have commonalities – construction detailing and trade skills.

The NZ leaky home issue may be seen more conspicuously in the monolithic cladding form of construction prevalent during the period, however the route cause is as ever the attention (or rather the lack of it) to detail in design, material specification and installation skills.

The US issue is not as conspicuously visualized through a design style, but is being put down to the hyper demand for new construction which led to poor construction technique as a function of inadequate training and supervision as the industry sucked in thousands of workers to meet the burgeoning demand.

The scale of the problem is strikingly highlighted in the article by reference to a 25 storey apartment tower in Seattle which is being demolished even though it is only 10 years old. The tower pictured below has been found to have been built without adequate corrosion protection on the supporting steel cables in the concrete structure (Seattle Times report).

Article Discussion

  1. Lara says:

    I wonder if any of the apartment buildings erected in Wellington in recent times might have similar issues due to the speed of construction. Could we see some of these buildings dismantled within 10 years like this Seattle disaster?

    Also wonder how a large earthquake would impact on some of the more recently built Wellington structures – could they simply collapse like a house of cards or simply rot away over time – certainly plenty of examples of shoddy construction locally:

    “Other prominent cases of leaking buildings discovered include Marion Square, a 40-unit apartment complex in inner-city Wellington, which was contaminated with stachybotrys, a toxic mould.”

    “An Oriental Parade apartment block, with an estimated repair bill of $4m, also settled out of court in a confidential settlement. Details of the deal – thought to be one of the city’s biggest leaky-building settlements – for the apartment block at 166 Oriental Parade are confidential. Even the Weathertight Homes Tribunal is unaware of the final figure.”

    “In 2011 the Ronald McDonald House for children with cancer and their families at Wellington Hospital is to be demolished as leaky and replaced; the building had been built in 1991 under the old building regulations”

    Many of the buildings affected by weathertightness issues have been apartment or townhouse developments. Before you buy an apartment or townhouse, you’ll want to know that it is structurally sound and weathertight. Some warning signs include:

    •Dampness, mould, musty smells, stains, bubbled paint, and other signs of moisture.
    •Rot, cracks, rust, holes or other signs of damage in the cladding, roof and other parts of the building?s exterior.
    •Springy or sloping floors.
    •Piles that are soft when you push a screwdriver into them.

    Here is a checklist for buying an apartment:

  2. Mat says:

    Yes Lara you raise some very good points.

    Coming from a trade background I have heard worrying rumours about rampant cost cutting by developers in the lastest round of apartment constructon. Its likely most of the recently constructed apartment blocks (like Soho etc) in Wellington would be suspect. I certainly would not touch an apartment with a barge pole.

    Interesting how in the Seattle case, what could appear (to a layperson) an apparently minor issue like the supporting cables not being treated was enough to condemn the entire building.

    Certainly given whats happened in Chch now with the latest quake, the issue of total structural failure becomes a very real concern.

    Its hardly surprising banks are wary of lending on apartments.

  3. Alistair Helm says:

    My thanks to Mat and Lara for extending the debate on this issue. I think the events of this week in NZ have brought a heightened sense of awareness to the issue of building safety.

    I know from personal experience the regard with which the NZ building code is held internationally in regard to earthquake impact, my hope is the code adequately covers the design detail required for durability and that construction standards are being adequately monitored. As is so often said it is what you cannot see that is the potentially the most damaging.

  4. Lara says:

    One of the ChCh collapsed buildings – either the PGG or CTV building were supposedly “earthquake engineered” on rubber isolating feet etc yet look what happened – total failure.

    If the ground under the structure does liquify it doesn’t matter what method of foundation is used – the building will still be likely to collapse no matter how well engineered!

  5. Russell says:

    If you are looking at any properties with Harditex, Solid Plaster, Plaster over polystyrene, Plaster over chicken wire etc, etc then be aware that chances are if it is not leaking now it will at some future point particularly if it has no eaves, includes parapets or flat roof areas.

    Always ask the real estate agent:

    What is this exterior system?
    Does the house have treated framing?
    Has a cavity cladding system been used?
    When exactly was the house built?
    Does the house have any known problems?
    Has a building report been obtained?
    Have any offers fallen through due to a failed building report?

    Before you make an offer check that your bank will actually provide a mortgage to finance the purchase of a property with the type of construction outlined above and built in the period from 1992 to 2005 – many will not!

    Then get your own building report which includes infrared moisture detection and/or invasive testing and factor in at least $200,000 for a future reclad when making an offer.

    If problems are found ask for a hefty discount – at least double what you may be quoted for repairs.

    Also remember that homes as described above will always be more difficult to resell in the future and are not likely to not keep up with values in comparison to a standard weatherboard house built earlier than 1990.

  6. Adrie says:

    Rotorua 28-07-2011.

    Subject ; I am embarrassed to be part off the Building Industries.

    The Building industry is governed by two Documents.
    The Building act and the Building Code

    The building act is given the rules or regulation we have to comply to.
    The building code is a performance based document.

    Nor the Building Act or the Building Code is prescriptive in how to build.

    The Building act refers many times to product certification in able to pass on the right information to the designer or the Territorial Authorities. To make sure on reasonable grounds that the design complies with the Building Code.

    It appears that DBH is failing to administer the Building act in relation to section 269 Issue of product certification. This section of the Act is one of the keys to meet compliance with the Building Code.

    The DBH , allowed section 269 Issue of Product certification to be replaced by a Product appraisal issued by Branz.

    Product appraisal ; Definition supplied by Branz.

    One off the keys to meet compliance with the Building Code has been taken away.

    The DBH provides 35 compliance document in accordance with section 22 of the Building Act 2004. Compliance Documents for use in establishing compliance with the building code , Section 22 subsection (3) reads ; subject to any regulations referred to in section 20.

    Section 20 of the building Act 2004 : Regulations may specify that there is only one means of complying with the building code. Section 20 subsection 2C reads ; Building Methods or products that have a current product certificate issued under section 269.

    It appears that without product certification the Compliance document are not complying with the Act and there for not complying with the Building code.

    Section 49 ; Grant of Building consent. A building consent authority must grant a building consent if it is satisfied on reasonable grounds that the provisions of the building code would be met if the building work were properly completed in accordance with the plans and specifications that accompanied the application.

    It appears that by granting a building consent the Building consent Authorities are making the decision that the submitted drawings and specifications comply with the NZ building code and there for the NZ building Act 2004.

    In the above we have shown that the construction industry can not comply with the NZ Building code for the reason it does not comply with the Building Act 2004

    The Leaking Homes at a cost of 20 Billion dollars is a confirmation of the deficiencies in administering The building Act 2004 by DBH and for allowing Branz to mislead the construction industry.

    To make madders worse DBH is trying to recover money to pay for there own , Branz and The Territorial Authorities , deficiencies. It introduced the Weathertight Homes Resolution Services Act 2006.
    And it started the propaganda by putting the blame on the Builders.

    If the DBH is failing to administer the Building Act 2004 and Branz is misleading the Industry and the Territorial Authorities grant permits on application that do not comply with the Building Code how can the Builder be successful in building a construction that complies with the building code ???

    It would seem we have learnt nothing from the Leaky Home crisis

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