Getting a building consent

By Trevor Pringle - 1 June 2004, Build 82

If you want the building consent process to go smoothly, the consent documents must clearly show how the building will meet the performance requirements of the New Zealand Building Code. If they don’t, the process will be delayed while further evidence is provided.

Any building consent documentation must provide sufficient evidence to enable the Territorial Authority staff, or a Building Industry Authority approved building certifier, to readily determine that the proposed project will comply with all relevant performance requirements of the New Zealand Building Code.

Consent applications that lack information to show compliance with the Code are likely to be put on hold until further information can be supplied. The reasons for being put on hold could include:

• critical details missing

• details given are not considered able to meet the performance requirements

• details lack essential information

• materials, such as claddings, fixings or finishes, to exit-ways are not identified

• materials are considered inappropriate for the situation, for example, insufficient durability

• producer or other supporting evidence is not acceptable.

What should documents contain?

A ‘good’ set of consent documents:

• accurately represents the site conditions, levels and boundaries

• accurately represents the extent and content of the project by defining the work to be done and the materials to be used

• demonstrates compliance with the relevant sections of the Code.

Define work and materials

The set of documents must also:

• include a site plan, floor plan(s), all elevations, cross sections, construction details, specification and supporting evidence, such as structural calculations and reference standards

• be presented clearly and concisely in a logical sequence, avoiding repetition and non-essential comment

• be drawn to scale with dimensions shown

• show finished and original ground levels accurately.

Demonstrate compliance

Drawings and specification clauses must show:

• actual materials, fixings and finishes (wall cladding, roof cladding, underlays etc.) to be used to ensure durability requirements (to satisfy B2) will be met

• how water is to be kept out of the building (to satisfy E2), aspects to be covered include: specific cladding used, window, door and flashing details; junctions between elements; roof and wall penetrations

• how structural adequacy is achieved, which includes structural and bracing calculations, clear identification of the wind zone and design loadings

• the means of achieving fire safety

• finishes to surfaces where hygiene and fire performance requirements apply

• construction and dimensions of barriers and handrails

• how the requirements of clauses G1–G14 are complied with, this includes natural light, ventilation, intertenancy acoustic privacy, plumbing, hygiene, surface finishes, drainage

• how the thermal performance of the building meets the requirements for internal moisture (E3) and energy efficiency (H1) (using NZS 4218 or specific thermal design).

Work not covered by an Acceptable Solution

An Acceptable Solution may not cover a significant part of any project and in these cases it is up to the designer to prove compliance with the performance requirements of the Code. Supporting information can be producer statements, product appraisals, trade literature, BRANZ Appraisal Certificates, recommendations/drawings from BRANZ’s Good Practice Guides, and BIA Accreditation Certificates. Where used this supporting information must:

• be relevant to the project or material being considered (‘general’ producer statements should not be used as they are not specific to the project)

• clearly state what items are covered, for example, a producer statement may cover the durability of a given product or it may cover the structural adequacy of a proprietary building system.

There must also be a paper trail to support the use of a particular building material where the manufacture of the item is not covered by a New Zealand or other recognised standard.

Once the documents are completed, but before they are submitted, it’s a good idea to cross-check them to ensure they show compliance with all aspects of the Code. Once this is done the consent process should be a straightforward process.