Alteration of an existing building

Changes made to an existing building are considered to be an alteration. This may include, for example, increasing or decreasing the floor area, making or closing an opening, erecting or demolishing a wall etc.

Usually this requires a building consent, but it will depend on the extent of work being undertaken - check the Council and the Ministry of Business, Innovation and Employment's guidance on building works that do not require consent.

When thinking about altering an existing building,  there are a number of requirements you need to know about.

The building consent can only be granted where the building consent authority/territorial authority is satisfied that the building will:

• comply as is reasonably practicable with the Building Code provisions for means of escape from fire and access and facilities for people with disabilities (as required)
• continue to comply with the other provisions of the building code to at least the same extent as before the alteration.

Building consent authorities are allowed to grant building consent for the alteration of an existing building. The Act clarifies that if part of a building is altered, upgrade provisions for the rest of the whole building are triggered.

When applying for building consent to alter an existing commercial building, you will need to provide a suitable report covering means of escape from fire (fire report) and access and facilities for people with disabilities.

If you are altering a building that is subject to an earthquake prone building Notice, section 133AT of the Act provides additional upgrade exclusions.

When altering a commercial building make sure the design professionals have appropriate skills, experience and competence to make the application to avoid your application being suspended or refused.

MBIE has developed a five-step process including a simple flow chart that will help you to understand how you can meet the requirements and the information you will need to provide.