Each has advantages and disadvantages in terms of cost and on-going impact on the building – including its structural performance, marketability, value and occupant health. BRANZ recommends that the designer document the reason for adopting a particular option.

Weathertightness remediation also offers the owner an opportunity to consider other changes to the building – to increase its amenity and value, remedy other defects, reduce the risk of further weathertightness problems and improve sustainability.

The approach to remediation should always be made on a principled basis, taking into account all issues ranging from the type of cladding and extent of leaks and damage to development opportunity. In most cases, it is necessary to consider all factors to be able to make the most appropriate repair recommendation.

If the building has not met minimum Building Code performance requirements (for example, 15 years for wall cladding, 50 years for wall framing), remediation work is likely to need a building consent.

In a situation where the client brief is to 'do the minimum', there must be sufficient investigation completed to determine exactly what this repair is.

It needs to be stressed that the assessment, design and repair of leaky buildings should be carried out by people with specialist expertise in the area. Repairs should not be carried out on a DIY basis or by a builder with no particular experience in these repairs. Many buildings have had repairs carried out that have not been effective. The buildings have continued to leak or have developed other problems.