Building consent application documents must specifically state the means of compliance for relevant Building Code provisions.
The drawings and specifications must clearly set out how compliance is to be achieved. This means they must show clearly and in detail:
- full compliance with an Acceptable Solution, or
- how compliance is achieved using a Verification Method, or
- if an alternative method is proposed, how the Building Code’s specific performance requirements are being met – if producer statements are part of the solution, they must be supplied. If the BCA believes that the proposal will be Code compliant, it is consented as an Alternative Solution.
It is not sufficient just to reference a New Zealand standard (such as NZS 3604) or an Acceptable Solution or cite manufacturers' recommendations without being specific about which option is being used and how it will be implemented. (If this is done, even if the BCA approves the plans, subsequent supervision may be inadequate, raising the risk of building failure down the track.)
The following information should also accompany the building consent application, even if it does not form part of the building contract:
- Documentation about the reasonable practicality of achieving full compliance for existing buildings (other than single residential).
- Wind zone assessment (unless provided by the territorial authority in the PIM).
- Weathertightness risk assessment (the risk matrix of Acceptable Solution E2/AS1 is a useful starting point to highlight the risk areas of the design. Further risk analysis is required where the building is outside the scope of E2/AS1).
Documentation that is sometimes missing from building consent applications:
- Information as to why it is not practicable to achieve full compliance for existing buildings with respect to Building Code performance triggered for upgrade.
- Wind zone assessment where there is no territorial authority assessment or the site has been assessed as specific design. Buildings on a site with wind speeds in excess of 55 m/sec (extra high) will need all structure specifically designed, and special consideration of all cladding including the design of window and door joinery – such buildings fall outside the scope of many Acceptable Solutions.
- Weathertightness risk assessment – the E2/AS1 risk matrix is only applicable for buildings on sites with a wind speed of up to 55 m/sec and within the scope of E2/AS1.
- Producer statements and other information that support a claim for Building Code compliance where there is an Alternative Solution. This is particularly common where the proposal is a variation on an Acceptable Solution detail or the site conditions fall outside the scope of the Acceptable Solutions.
- Details and location of specified systems and procedures for their inspection and maintenance.
The Building Act requires BCAs to decide that the building as built complies with the building consent before a Code compliance certificate can be issued. The BCA must also keep accurate records of the construction.
Both these requirements have implications for the recording and approval of variations from the approved consent documents during construction. Where the change is not significant to compliance with the Building Code, the BCA may be willing to informally record the change on the site records. Otherwise, a formal amendment to the building consent will need to be approved by the BCA.
Updated: 30 October 2015