How did the leaky building crisis occur?
The leaky building crisis is a result of a combination of factors in the late 1990' and early 2000's that resulted in the construction of a large number of buildings that were vulnerable to moisture ingress. Those buildings were:
Designed in a way that made them susceptible to moisture ingress - the common design features of many leaky building (although not all) is the Mediterranean look with parapets, flat roofs and frequently little or no eaves.
Built with face fixed cladding systems which relied to a large extent on the total exclusion of external moisture to meet the external moisture and durability requirements of the Building Code and provided little or no margin for error if moisture ever did penetrate behind the cladding and into the building cavity.
Built using untreated kiln dried framing timber which had recently been approved by the Building Industry Authority as a material that met the durability requirements of the Building Code but which was particularly susceptible to any moisture ingress. This meant that by the time the homeowner realised that there was a problem it was already too late to fix it without rebuilding significant parts of the structure of the building.
Built by developers who had no incentive to pay for the proper design of the buildings let alone the appropriate level of supervision of construction to ensure that the buildings were built properly. Mostly these developers used a company to carry out the development which was then wound up after all of the units were sold letting the developer take the profits but avoid any liability if anything went wrong.
Built at a time when there was a boom in the housing market in New Zealand and a large number of builders with little or no industry related qualifications or experience who were carrying out often quite complex construction work with little or no supervision.
Built at a time when the last line of defence for the homeowner (the territorial authorities and building certifiers responsible for ensuring buildings met the minimum standards for construction in the Building Code) were not meeting their obligations under the Building Act 1991 to take all reasonable steps to ensure that buildings were built in accordance with the Building Code.