This option is suitable for minor variations from Acceptable Solutions.
This option is based on an Acceptable Solution or Verification Method, but with minor variations. The designer compares the performance of the proposed Alternative Method with the performance principles in the Acceptable Solution.
The comparison must be relevant, and it must be directly comparable in aspects such as use, situation and environment. The Alternative Method proposed may be more or less robust than the Acceptable Solution as long as its performance meets Code requirements.
As compliance documents provide solutions that are ‘deemed to comply’ with the Building Code, Acceptable Solutions can provide sound guidance for determining Alternative Solutions.
Compliance path 1 is likely to be used where the principles of the Acceptable Solution can be shown to apply to the renovation work. Some examples might be:
- application of flashing cover dimensions that are based on those given in Building Code Acceptable Solution E2/AS1
- subfloor fixings selected in accordance with Section 4 of NZS 3604 for durability
- the proposed use of flexible flashing tape in the preparation of openings
- the proposed use of air seals around windows.
The documented evidence to the BCA should:
- identify which Acceptable Solution or Verification Method your proposal is being compared with
- identify the similarities between the proposed method and the Acceptable Solution
- identify areas of difference and provide evidence that any differences will not detrimentally affect performance under other Building Code clauses
- identify and address areas where there may be a need to compensate for differences, for example, a flashing dimension has been increased to provide additional cover because of the exposure of the detail to the weather
- demonstrate that the proposed solution will comply with relevant Building Code requirements.
The BCA does not have to accept the performance claims made as part of a comparative solution, so the designer will have to provide relevant and convincing evidence.