Alterations to existing buildings

Section 112 (external link, new window) requires that an alteration must not cause a compliant building to become non-compliant, or a non-compliant building to comply to a lesser degree. Please refer to section 112(1)(b).

It also ensures that existing buildings have good standards of fire safety and access for people with disabilities. It does this by requiring that existing buildings comply as nearly as is reasonably practicable with means of escape from fire and access and facilities for persons with disabilities (if this is a requirement in terms of section 118, external link, new window). Please refer to section 112(1)(a).

Section 112 (2) provides an alternative compliance path. This can be used when the proposed building work provides improvements to means of escape from fire, or access and facilities for persons with disabilities and those improvements outweigh the detriment of the building not complying with the relevant provisions of the building code.

Section 112 (3) is subject to section 133AT (external link, new window) and deals specifically with alterations to buildings that are subject to an earthquake-prone building notice.

More information on what earthquake-prone means and what responsibilities you have as an owner of an earthquake-prone building can be found on the MBIE website (external link, new window).

In the case of alterations to domestic dwellings, compliance with section 112 is typically very simple. Designers are tasked with ensuring that alterations do not cause a compliant building to become non-compliant, or a non-compliant building to comply to a lesser degree under section 112(1)(b).

Domestic dwellings are not required to provide access and facilities for persons with disabilities. To comply as nearly as is reasonably practicable with means of escape from fire, many dwellings will only need to ensure they have compliant smoke alarms installed.

For many other types of buildings, such as commercial buildings, apartment buildings and public buildings, complying with section 112 requires a high level of understanding. When preparing building consent documentation, it is up to the owner or their agent, to prepare a case to demonstrate that they comply with section 112.

Our role is to consider the case and determine whether the required level of compliance has been met.

Domestic dwellings

Building consent applications should include accurate floor plans with all rooms labelled and showing locations of existing smoke alarms.  Please also indicate if smoke alarms are stand alone or interconnected throughout the dwelling.

Buildings other than domestic dwellings

Building consent applications should include a cover letter or similar outlining how compliance with section 112 will be achieved. They will often require fire and accessibility reports and details of upgrade work that will take place to bring the whole building up to the required standard.

Failure to provide comprehensive and legally compliant information is a common cause of delays and refusal of building consent applications.

Fire report and fire safety information - what is required: 

The Ministry of Business, Innovation and Employment (MBIE) has developed guidance on requesting information about means of escape from fire for existing buildings. This guidance uses a building score sheet. It takes into account the building age, information already held by Council, extent of the proposed building work, building importance level and presence of sleeping facilities. This is often considered to be a risk assessment.

Full information can be found on the MBIE website (external link, new window).

We need to keep in mind that section 112 focuses on the existing building. All alterations to existing buildings also involve new building work. New building work must fully comply as required by section 17 of the Building Act (external link, new window).

We can highlight this principle by considering a case where an owner replaces a window in an existing non-compliant boundary fire wall. Even though the wall may provide little or no fire resistance, the new window is considered to be new building work and must be fully compliant and provide the required fire rating.

For further information, advice or to arrange a pre-application meeting please contact us on 03 477 4000 or email building@dcc.govt.nz.

The following links provide comprehensive guidance and resources designed to assist with the building consent application process:

• DCC guidance - Alterations to existing buildings
• NZ Legislation - Building Act 2004 section 112
• NZ Legislation - Building Act 2004 section 133AT
• Altering an existing building - MBIE guidance