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Protection from Fire

Frequently asked questions  

Since publication on 10 April 2012, the Acceptable Solutions and the Verification Method for Protection from Fire (C/AS1-C/AS7 and C/VM2) have been subject to an ongoing process of continuing improvement. Many of the improvements have been and will be informed by feedback and requests for clarification.

The FAQs are split into the following sections:

If a building complies with an Acceptable Solution or Verification Method for Protection from Fire as adjusted by the interpretations listed on this site, it is also deemed to comply with the Building Code, and it does not need further specific engineering design.

The intent is that the interpretations produced here may be incorporated in the next amendment of the Acceptable Solutions, Verification Method and commentaries as required.

If you can't find the answer to your question here, you can use our 'Ask a question' form.


1. Acceptable Solution’s C/AS1 – C/AS7 interpretations

In this section


1. 1 What fire safety systems do “storage buildings capable of storage of 5.0m or greater but with an apex of less 8m and a floor area of than 4200m2” designed in accordance with C/AS5 require?

A Type 3 alarm system is required. A direct connection to the Fire Service is not required where a phone is available at all times for 111 calls, and

A Type 18 building fire hydrant system is required, unless the Fire Service hose run distance for Fire Service vehicular access to any point on any floor is less than 75m.

Where occupancies or escape heights are in excess of the thresholds defined in C/AS5 for a Type 3 system, the requirements driven by occupancy or escape height take precedence.

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1. 2 Is it possible to use the average wall height as the height of the enclosing rectangle for facades with non-uniform heights, when using the method set out in C/VM2 commentary A.3.0 Method 2?

A.3.0 - Method 2 - Step 2 should be read as including the following additional text: “Where, due to the building height slope or the building shape, the height of the enclosing rectangle is not constant, the height shall be taken as the average height across the width of the wall being considered”.

The text will be incorporated into the C/VM2 commentary in due course.

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1.3 Are there any exceptions to the requirements of the Acceptable Solutions to extend an alarm or sprinkler system throughout a building?

The Acceptable Solutions for Protection from Fire require a fire alarm system and fire sprinkler system to be extended throughout a building, if a system is required in any part of the building.

However, the following exception applies where a single-storey building is separated at the ground floor into two or more unit titles, with fire separations (designed with the relevant property rating) between each unit.

Figure 7.1 Single Storey Commercial Building

Figure 7.1

If Title 1 has a fire sprinkler system installed, Titles 2 and 3 may be unsprinklered (provided there is no other requirement to install a system in those titles). They are effectively treated as separate buildings.

This does not apply in a multi-storey building where the floors are unit title separations/boundaries.


C/AS7 also allows for sprinkler protection of the car park firecell when the criteria of C/AS7 2.2.3 have been met.

The Acceptable Solutions for Protection from Fire allow a heat detection system to be installed in certain areas in lieu of a smoke detection system.

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1.4 Where C/AS2 paragraph 4.9.6 c refers to “Have more than one direction of escape” does this mean two separate exits from within the household unit or a choice of route at the unit’s front door?

Clause 4.9.6 reflects a point of choice at the front door.

It should be noted for completeness that dead end travel distance limits within the apartment must be achieved.

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1.5 Where C/AS3 2.2 refers to 100 people in care or detention, is this 100 in the building or in one firecell?

It should be read as being 100 people in care or detention within the “building”.

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1.6 What was meant where Acceptable Solution Paragraph 4.15.6 says “Any space between ceilings and roofs or floors above shall not exceed 400m² in area, measured at ceiling level, and 30m in length or width?”

It should be read as "any space between ceilings and roofs or floors above

a) shall not exceed 400m² in area, measured at ceiling level, and
b) shall not exceed 30m in length or width."

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2. Verification Method C/VM2 interpretations

In this section:


2.1 Where a challenging fire is placed in the main entrance lobby of a building is it appropriate to consider the occupants evacuating through the balance of the exits for this ASET vs. RSET?

Yes, noting that for the other challenging fire scenarios in this building 50% of the occupants should be considered as evacuating via the main entrance for the ASET vs. RSET analysis.

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2.2 Why doesn’t Table 3.3 (Pre-travel activity times) in C/VM2 give a time for a voice alarm signal for spaces in which the occupants are sleeping and familiar with the building?

The table reflects the current requirements in NZS 4512 and acceptable solution F7/AS1 for alarm systems that alert occupants who are sleeping and familiar with the building. Voice alarms are not required in these spaces.

Should a voice warning sound be used in lieu of the tonal sound, then the pre-travel time should be as per the tonal time (this reflects that the critical factor in a residential setting pre activity time is the time to awake).

For more information:

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2.3 Ask a question

If you can't find the answer to your question above, you can use our 'Ask a question' form.

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3.0 Procedural issues

In this section:


3.1 Is there any guidance on assessing ‘means of escape from fire’ for alterations to existing buildings?

The Ministry of Business, Innovation and Employment (MBIE) has developed “Guidance: Requesting information about means of escape from fire for existing buildings - A guide for Building Consent Authorities and Territorial Authorities” to help Building Consent Authorities (BCAs) or Territorial Authorities (TAs) decide what information on means of escape from fire to request, as part of a building consent application, to alter an existing building.

Where an ANARP assessment of means of escape from fire is undertaken using the C/VM2 method, the FEB process is part of that method.

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3.2 When does the Fire Service Commission become involved in a building consent application?

New Buildings for Protection from Fire using the Acceptable Solutions (C/AS1 – C/AS7) or Verification Method (C/VM2) do not need to be sent to the Fire Service commission at the consent stage.

Designs need to go the Fire Service Commission for advice if:

  • compliance with clauses C1-6, D1, F6, or F8 of the Building Code will be established by alternative solution – this would be the case, for example, for building types such as power generation plants, dairy factories, sub-surface buildings, or tunnels (the scope of the Acceptable Solutions or the Verification Method does not include these types of buildings)
  • the consent application involves a modification or waiver of clauses C1-6, D1, F6, or F8 of the Building Code under Section 67 of the Building Act 2004
  • the consent application is for an alteration, or change of use to an existing building, except where the effect on fire safety systems is minor.
  • Building is not an exempt building. The following buildings are exempt:
    • single household unit
    • vertically separated household unit with independent egress
    • outbuilding or ancillary building
    • internal fit out-unless it relates to ‘change of use’
    • outbuildings or ancillary buildings
    • premises of diplomatic missions
    • any Crown buildings specified by Gazette notice.

For more information

This explains the requirements of the gazette notice of 3 May 2012 and clarifies when a design needs to be sent to the Fire Service Commission.

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3.3 When is a fire-engineering brief required as part of the building consent documentation?

If a building consent application uses the Verification Method C/VM2 to show compliance with Code Clauses C1 to C6, a fire engineering brief (FEB) process, including a FEB report, is required as part of the consent documentation. The FEB process has to involve all stakeholders in the building, including but not limited to, the following:

  • building owner and users
  • design professionals
  • Fire Service Commission
  • building consent authority (BCA)
  • insurer
  • test certifier, if hazardous substances are in the building.

This means that the Fire Service Commission is included in the design process at an earlier stage than previously.

For more information on FEBs

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3.4 What is the status of ‘old’ C/AS1 (2011) after 9 April 2013?

Since 10 April 2013, the ‘old’ Acceptable Solution C/AS1 (2011) is no longer a means of complying with the Building Code.

However, if a consent was lodged or submitted for consent with a BCA before 10 April 2013 for a design complying with the old C/AS1 (2011), then any proposed amendments to that consent must comply with the ‘old’ C/AS1 (not the Acceptable Solutions C/AS1-C/AS7- 2012).

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3.5 Are the uses in Schedule 2 of the Building (Specified Systems, Change the Use, Earthquake-Prone Buildings) Regulations 2005, affected by the Protection from Fire documents?

The Protection from Fire documents do not affect the ‘uses’ specified in Schedule 2 of the Building (Specified Systems, Change the Use, Earthquake-Prone Buildings) Regulations 2005.


The ‘uses’ specified in Schedule 2 are often confused with ‘purpose groups’ from Acceptable Solution C/AS1 (2011) and ‘risk groups’ from Acceptable Solutions C/AS1 to C/AS7 (2012). ‘Purpose groups’ and ‘risk groups’ are not related to ‘change of use’.

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3.6 How do I determine a ‘change of use’?

Schedule 2 of the Building (Specified Systems, Change the Use, Earthquake-Prone Buildings) Regulations 2005 helps identify if there is a change of use to the building.

To determine if there is a ‘change of use’ to a building:

  • Firstly, refer to Schedule 2 of the Building Regulations (Specified Systems, Change the Use, Earthquake-Prone Buildings) Regulations 2005 to confirm if the building is being used for another function. For example, changing a building’s ‘use’ from apartments (SR) to a day-care centre (CS).
  • Secondly, determine if the new use is more onerous than the old use in terms of complying with the Building Code. In the above example, a day-care centre would be more onerous as there are additional Building Code requirements including more fire safety requirements and additional requirements for access and facilities for people with disabilities.

If both of the above are satisfied, then the proposed new use is deemed a ‘change of use’.

For more information on ‘change of use’

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3.7 Is there any guidance about ‘change of use’ under section 115 of the Building Act?

MBIE published guidance for Change of Use for the Christchurch City Council to help them deal with changes of use for temporary business and/or housing relocations because of the Canterbury earthquakes. Although developed for Christchurch, the guidance explains the ‘change of use’ provisions in the Building Act and associated regulations, and provides practical advice on how to apply these.

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3.8 Which Building Code clauses are relevant to assessing the attributes of a building that relate to ‘means of escape from fire’ (as referred to in sections 112 and 115 of the Building Act 2004)?

When the Building Act 2004 requires an assessment of the ‘means of escape from fire’ in a building, compliance with the following Building Code clauses must be considered:

C3.4 Fires affecting areas beyond the fire source »
C4 Movement to place of safety »
D1 Access »
F6 Visibility in escape routes »
F7 Warning systems »
F8 Signs »

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3.9 Will past determinations applied to the superseded C1 – C4 Building Code Clauses be applicable as guidance for the current C1 – C6 Building Code Clauses?

Determinations applying to Code Clauses C1-C4 and C/AS1 (2011), do not apply to the current Code Clauses C1-C6 and the Acceptable Solutions C/AS1-C/AS7, and Verification Method C/VM2 (2012).

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3.10 Can a design based on the Acceptable Solution incorporate aspects of the Verification Method and still comply with the Building Code?

A design based on an Acceptable Solution, (C/AS1 to C/AS7) must completely comply with all the requirements of the Acceptable Solution. It cannot incorporate aspects of the Verification Method and still be used to show compliance with the Building Code.

However, there is one exception, when the only non-compliance with the Acceptable Solution relates to the prevention of horizontal spread of fire. In this instance, a suitably qualified fire engineer may use the C/VM2 methodology to show compliance with this aspect of the Building Code.

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3.11 Where can I find the Code clauses, Acceptable Solutions, and Verification Methods referenced in these questions and answers?

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