Building consents for imported ancillary buildings

It is often difficult for building consent authorities (BCAs) to check that imported kitset ancillary buildings, such as farm buildings and garages, will meet the relevant performance requirements of the New Zealand Building Code for specific building consent applications. This is because there is either limited design information or they have to use the design information in trade literature that is based on another country’s requirements.

Design information prepared for another country's use needs to be interpreted for New Zealand. For example, an Australian-developed system which claims a garage was suitable for Wind Zone N2, would be suitable for use in all building wind zones up to and including a NZS 3604 Medium Building Wind Zone.

There are also issues with other Code clauses. For example, there may or may not be any claims made with regard to the durability of components. All components, particularly fixings, need to be assessed against requirements for the specific application, including the site location. In addition to checking structural performance, particular attention should be directed towards the durability of framing members (eg, timber treatments) and fixings.

Proprietors or distributors of these ancillary buildings will make BCAs' jobs much easier if the design information, including trade literature and technical back-up (calculations etc), has been specifically prepared for the New Zealand market, and if it addresses all Code requirements.

BCAs should also be vigilant as, even where design information has been prepared to cover New Zealand applications, that information may be incomplete or require further questions to be asked or investigations to be carried out.

If it is unclear whether the system in a particular application will meet the Building Code, the BCA should obtain a regulatory peer review of the consent application or apply, in the event of a dispute with an applicant, to the Department for a determination.