Introduction to altering an existing building

It's important for building consent applicants, building professionals and building consent authorities to understand the requirements for altering an existing building.

Altering an existing building can trigger certain requirements, including:

  • ensuring the building continues to comply with the Building Code to at least the same extent as before the alteration, and
  • complying 'as nearly as is reasonably practicable' (ANARP) with current Building Code requirements for:
    • means of escape from fire (referred to here as 'fire')
    • access and facilities for persons with disabilities (referred to here as 'accessibility')
  • undertaking seismic work so that the building is no longer earthquake prone (for a substantial alteration (defined in regulations) to an earthquake-prone building).

The guide will be of interest to:

  • building consent applicants, whether building owners, or building professionals on behalf of clients
  • building professionals including architects and designers
  • building consent authorities (BCAs) and territorial authorities considering building consent applications and determining whether or not to grant a building consent.

This guide helps you determine the requirements for proposed alterations to existing buildings, whether earthquake prone or not, and how these can be met.

This guide does not replace the decision-making powers of BCAs and territorial authorities in relation to alterations to existing buildings.

New building work associated with an alteration must comply with the Building Code. This advice does not apply to establishing compliance of new building work with the Building Code.

How helpful was this information?

Please note your feedback is anonymous. If you need a response, contact us.

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: