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Managing building alterations

The rules for managing building alterations are primarily contained in section 112 of the Building Act, and section 133AT of the Building Act for earthquake-prone buildings.

Under the Building Act 2004:

  • Section 112 sets out the requirements for altering an existing building that is not earthquake prone.
  • Section 133AT sets out the requirements for altering an existing building that is earthquake prone, issued with an earthquake-prone building notice (EPB notice). This must be used instead of section 112.
  • Schedule 2 and Section 118 set out the types of buildings to which the requirement to upgrade access and facilities for persons with disabilities applies. Section 7 defines a person with a disability. Sections 117, 119 and 120 are also relevant for applying the accessibility requirements.
  • Section 7 defines means of escape from fire. The upgrade requirements for means of escape from fire apply to all existing buildings undergoing an alteration.
  • NZS 4121:2001 is an Acceptable Solution to the Building Code for accessibility requirements.


  • The Building (Specified Systems, Change the Use, and Earthquake-prone Buildings) Regulations 2005 define the term ‘substantial alterations’ for earthquake-prone buildings subject to section 133AT of the Building Act.

Certain clauses in the Building Code relate to building alterations:

  • means of escape from fire – clauses C3.4, C4, C6, D1, F6, F7, F8.
  • access and facilities for persons with disabilities – clauses D1, D2, F7, F8, G1, G2, G3, G5, G9, G12.

You can find the following on the Legislation website:

NSZ 4121:2001 Design for Access and Mobility is available on the Standards New Zealand website.

Building Code compliance has the Building Code clauses.

Earthquake-prone buildings: substantial alterations has more information.

Requirements of sections 112 and 133AT of the Building Act

Sections 112 and 133AT require:

1. The building's overall compliance with the Building Code (including other applicable clauses in addition to fire and accessibility, such as structure) must not be less than what it was prior to the alteration taking place.

2. The whole building needs to be upgraded so that it complies as nearly as is reasonably practicable with the current Building Code clauses for fire and accessibility (if applicable under section 118 of the Building Act).

The applicable Building Code clauses for fire and accessibility are:

Means of escape from fire

  • C3.4 Fire affecting areas beyond the fire source
  • C4 Movement to place of safety
  • C6 Structural stability
  • D1 Access routes
  • F6 Visibility in escape routes
  • F7 Warning systems
  • F8 Signs

Access and facilities for persons with disabilities

  • D1 Access routes
  • D2 Mechanical installations for access
  • F7 Warning systems
  • F8 Signs
  • G1 Personal hygiene
  • G2 Laundering
  • G3 Food preparation and prevention of contamination
  • G5 Interior environment
  • G9 Electricity
  • G12 Water supplies

3. If the building being altered is earthquake prone and the alteration is a substantial alteration, section 133AT of the Building Act also requires the alteration to include the necessary seismic work so the building is no longer earthquake prone.

If building owners do not meet requirements 1 and 2, territorial authorities do have discretion to grant a building consent for a proposed alteration that does not comply. The criteria that must be met to apply this discretion are different for section 112 and section 133AT for earthquake-prone buildings. These are explained in Step 5 of this advice.

Other provisions include:

  • the requirements for alterations to buildings with an intended life of less than 50 years, set out in section 113 of the Building Act
  • the resource consent requirements for heritage buildings and forwarding the relevant building consent application to Heritage New Zealand
  • the requirement to notify Fire and Emergency New Zealand of any alteration that affects a building's fire safety systems
  • the additional detail required in building consent applications for buildings being altered that contain specified systems subject to a compliance schedule
  • the requirements for alterations that also involve a change of use, set out in section 115 of the Building Act
  • whether a certificate for public use is required when the public are still required to use the building while it is being altered, until a code compliance certificate is issued
  • whether the building consent is subject to a waiver or modification of the Building Code, noting that waivers or modifications of the Building Code relating to access and facilities for persons with disabilities for existing buildings can only be granted through a determination.

The Building Act is available on the Legislation website

How to support your building consent application provides more information on additional considerations required when preparing or checking a building consent application.

Earthquake-prone buildings: substantial alterations has more information.

Alterations requirements apply to the whole building

The requirements above apply to the whole building undergoing an alteration, not only the tenancy or space undergoing the alteration work. Where there is a group of buildings, eg a campus, these requirements only apply to the building that is undergoing the alteration.

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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: