Know your stuff: Exempt Building Work, Part 2

Posted: 27 July 2017

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Part 1 of this series covered off the basics of exempt building work and some of the easy to measure exemptions. Part 2 will go into a few of the more complex exemptions.
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As a brief recap, all building work requires a building consent, except for work exempted under Schedule 1 of the Building Act 2004. Schedule 1 lists the building work that is exempt from needing a building consent.

Building work that does not require a building consent is helpful and practical Schedule 1 guidance.

Don’t forget to check if you need a building consent. This will help you avoid fines from councils or penalties from the Building Practitioners Board. You can check by reading the Schedule 1 guidance and contacting your local building consent authority.

Exemption 8 – Windows and exterior doorways in existing dwellings and outbuildings

All work in connection with a window (including a roof window) or exterior doorway in an existing dwelling or outbuilding of not more than two storeys in height is exempt work.
However, if you are replacing a window or doorway, that item must not have failed its durability test under Clause B2 of the Building Code. Based on the current Building Code, this means that the existing item that is being replaced must have satisfied the 15-year durability requirement.

You will need to get a building consent if the item has rotted and needs replacing within 15 years of installation, or if the building work modifies a specified system (such as installing a roof window and repositioning a sprinkler head).

This exemption covers structural and/or weathertightness work as long as the purpose of that work is to install the window or exterior doorway.

Exemption 11 – Internal walls and doorways in existing building

Changing an internal wall or doorway is exempt building work unless the wall is:

  • load bearing
  • a bracing element
  • a firewall (ie a barrier designed to limit the spread of fire, heat and structural collapse)
  • part of a specified system (such as electromagnetic or automatic doors)
  • made of ‘units’ of materials stacked or bonded together with mortar (like bricks or blocks).

Exemption 12 – Internal linings and finishes in existing dwelling

You can replace any interior linings without using comparable materials in an existing dwelling without needing a building consent.

Interior linings could be part of bracing or fire resistant elements, so we suggest investigating and installing the appropriate type of replacement lining.

Exemption 13 – Thermal insulation

You don’t need a building consent to install thermal insulation in an existing building unless you are installing it in an exterior wall or an interior firewall.

Installing insulation in ceilings, floors and interior walls that are not firewalls are examples of exempt work.

Under the Residential Tenancy Act, ceiling and underfloor insulation will be compulsory in all rental homes from 1 July 2019.

Insulation on the Tenancy website has more information on this requirement.

Exemption 14 – Penetrations

Penetrations can be made that are 300mm or less in diameter can be made through both internal and external building components without a building consent for:

  • detached dwellings of any height and dwellings within a building that is not more than three storeys high
  • outbuildings that are detached and not more than three storeys high
  • all other buildings as long as doing so does not modify or affect
    • the primary structure
    • any specified system.

The exemption includes any associated building work like weatherproofing or fireproofing.

For other scenarios (such as a commercial building), creating a penetration – not exceeding – 300mm in diameter is still exempt building work if the work does not affect the primary structure or a specified system (such as a fire suppression system).

Exemption 35 – Alteration to existing sanitary plumbing (excluding water heaters)

Alterations to sanitary plumbing fixtures (baths, showers, basins, etc) are exempt from building consent requirements as long as you are not increasing the number of fixtures in the building and the alteration does not affect a specified system (such as fire sprinklers).

This work must be done by an authorised person (see page 79 of MBIE's guidance). It also excludes work for water heaters (although this work may be covered by other exemptions).

Next time…

The next article in our Exempt Building Work series will cover off the trickiest exemptions you’re likely to encounter. Stay tuned.


1) If you go to quote for a client to replace a window in their two-storey home, would you need to price in the cost of a building consent?

a. Yes, you need a building consent because the dwelling is two storeys
b. No, as long as it wasn’t installed less than 15 years ago and hasn’t leaked or rotted

2) Is work to remove my exterior wall exempt if I am removing it to extend my lounge over my deck?

a. You need to get a consent because it’s an addition and there are no Schedule 1 exemptions for external walls.
b. Yes, as long as it is not a firewall
c. It doesn’t require a consent because it’s a deck

3) I want to change my tongue and groove kitchen floor to plywood with a floating floor over it. I also want to install insulation beneath the floor. Can I do this all without a building consent?

a. Only if it the floor is not a bracing element
b. No, you can’t start without a building consent
c. Yes, it is exempt work
d. You can’t install the insulation without a building consent

4) I have been asked to cut a 150mm vent for a heat pump through a brick veneer wall. Can I do this without a building consent?

a. You need a brick and blocklaying LBP licence for that, but not a building consent
b. You need a building consent and a brick and blocklaying LBP licence
c. You don’t need a building consent for penetrations, but you need to be a registered electrical worker to do that work.

5) I am a roofing LBP and I want to cut a roof vent into an existing roof. How big can it be before I need a building consent?

a. You’re licensed as a roofer – you don’t need any building consents
b. 300mm in diameter
c. 100mm in diameter
d. 500mm in diameter

Check your answers

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: