Legal requirements of building consents

Under the Building Act, all building work must comply with the Building Code.

If you are planning on building a new house or doing alterations, you have to get a building consent from your local council before construction starts (unless it is work that is exempt).

To help explain the building consent and approval process, the Ministry of Business, Innovation and Employment has produced a booklet entitled The Building Act and You (896 KB), which contains essential information about your rights and responsibilities as you build or renovate. It tells you what you need to do at each step to ensure your building project is done legally, which will avoid potentially costly mistakes or delays. It also explains how the law will protect you if things don't go to plan.

Building Consent Authorities (BCAs) look at the detailed plans drawn by the registered architect or designer to see if the proposed house or building work complies with the Building Code. If it does comply, the BCA will issue you with a building consent allowing the work to proceed. When the house is finished, you apply to your BCA. The BCA conducts a final inspection and issues a code compliance certificate (CCC) if it is satisfied that the building work complies with the building consent.

You must apply for a CCC once the work is complete. If you do not apply within two years from the date your consent is granted, your BCA should contact you to follow up on the work.

Councils are required by the Building Act 2004 to keep information for the life of any building. This information will include the plans and specifications provided when applying for building consent, inspection reports by BCAs, and code compliance certificates.

This information can be researched, for example, when you are looking to buy an existing house.

Most people use the expertise of those in the building industry to advise them on the legal requirements of the building laws and many delegate the task of obtaining a building consent to their architect/designer, builder or project manager.

When you employ a registered architect or other type of designer, they must prepare plans and specifications that meet the Building Code performance standards or the building consent application won’t be approved by your BCA. The builder then has to build the house to the specifications and plans so that the end result matches what was approved in the building consent.

Ultimately you will be responsible under the Building Act if your house does not meet the required standards, so make sure you employ skilled people who know all the building controls and keep up-to-date with new standards and rules.

Subject to planning and resource management requirements, no one can make you achieve a higher or more restrictive standard than that which is required by the Building Code. In other words, when you are building a house or doing some other building work around home, provided it meets the minimum performance levels in the Building Code, you can be confident that your home will be sufficiently strong, durable, weatherproof, fire-resistant and use energy relatively efficiently. You must build the house to the specifications agreed in your approved consent.

However, there is nothing to stop you exceeding these performance levels if you choose. For example, you can use concrete tile roofing that exceeds the minimum standards and is likely to outlast you and your grandchildren. You are free to look for creative and innovative ways of adding features that improve your comfort and enjoyment of the house, providing they at least meet the minimum performance levels in the Building Code, and are checked as doing so through the building consent process.

Generally, only work specified in Schedule 1 of the Building Act 2004 is exempt from needing a building consent. Amendments to the Schedule came into effect on 16 October 2008.

The Ministry of Business, Innovation and Employment has a useful guide back-grounding the exemptions.

Some common examples are:

• Retaining walls up to 1.5 metres in height, providing they are not carrying any load other than the ground.
• Construction, alteration or removal of an internal wall of an existing building but only if structural stability is not reduced, the means of fire escape is not affected or the wall is not made of bricks, concrete blocks mortared together.
• Fences up to two metres in height (other than fences around swimming pools).
• Garden sheds that are less than one storey and less than 10 square metres in floor area which do not sanitary facilities or facilities for the storage of drinking water, and are not positioned any closer than the shed's own height to a boundary.
• Closing in an existing veranda or patio where the floor area does not exceed five square metres.
• Low platforms (deck) not more than one metre off the ground.
• Repairing or replacing part or all of a single story privately owned outbuilding.

Note that building work that is exempt from requiring a building consent must still comply with the Building Code.

If you are unsure, check the full version of Schedule 1 of the Building Act and ask your local council before doing any work as each of these examples may have certain limits and definitions.

Your local council may grant additional exemptions if they consider the work is likely to be carried out to the Building Code or, if not, is unlikely to endanger people or buildings.