"However, the difficulties involved in determining the extent of the problem on a scientific basis is that it may involve a degree of destructive testing of some parts of existing houses."
The report estimated if 50 per cent of apartment dwellings built in the last decade required an average $20,000 worth of repairs, it could cost between $120 million and $240 million.
However, it stressed there was a high degree of uncertainty in evaluating the cost as the full extent of the problem was hard to determine.
"Media reports have suggested a repair bill in excess of $1 billion, and statements have been expressed to the overview group such as "there is not an apartment unaffected," the report said.
"To the contrary, others have argued that it is a 'beat-up', that such figures are exaggerated, and that even our $120 million to $240 million estimate may be excessive.
"Even at the conservative end of the range, however, the scale of the problem is unacceptably high."
Having acknowledged that a significant problem existed, the building industry needed to act to address and remedy the problem and avoid its occurrence in the future, the report said.
However, with most cases regarding leaky buildings being settled out of court and being bound by confidentiality agreements, "there is no public record of them and therefore a barrier to accruing the very information needed for preventative action."
It would be counterproductive for the issue to be pursued in a "recriminatory" manner, the report said.
"Any formal procedures to remedy the problem should seek to draw in the sector as a whole in an attempt to find solutions which will have wide support."
The report called for a meeting of all representatives of relevant organisations and interest groups to be held to establish formally that the building sector acknowledged watertightness was a problem.
"The building sector must assume responsibility for doing something about it," the report said.
Other recommendations included:
* That the BIA resolve with the Ministry of Health the best way to identify and treat potential health risks associated with fungal decay.
* The BIA review and upgrade the criteria for what constituted a reasonable level of detail with respect to weathertightness, develop more prescriptive Acceptable Solutions and verification methods regarding external moisture, and sponsor research into developing effective moisture management systems.
* The BIA and Standards New Zealand develop and promote a standard for domestic building watertightness.
* That the BIA discuss with the Department of Internal Affairs the philosophy of "minimise compliance cost" to ensure building standards and quality were not compromised.
* The BIA and Building Officials Institute develop guidelines on the interpretation of the Building Act.
BIA chief executive Bill Porteous said the authority had already acted on some of the report's recommendations. Relevant parts of the building codes were being reviewed and the warning about balconies had been issued, he said in a statement.
"Others we will begin implementing immediately. One of these will be a public information campaign explaining the risk factors around leaking buildings and what to do if you think you might have a problem."
Internal Affairs Minister George Hawkins told reporters the report outlined "multi-faceted" problems which he hoped could be solved at a meeting of industry representatives rather than through costly litigation.
"The solutions will come through getting everyone together to talk about those."
He would attend a meeting of industry players which he had asked to be arranged within the month.
- NZPA
Report on Weathertightness of Buildings
* If you have information about leaking buildings,
email the Herald
or fax (09) 373-6421.
Further reading
Feature: Leaky buildings
Related links
