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Restricted building work (RBW)

Last updated: 21 March 2016

Find out about restricted building work and why you must use licensed people for some residential building projects. 

Restricted building work explained

‘Restricted building work’ is work that’s critical to make a home structurally sound and weathertight. You must use Licensed Building Practitioners (LBPs) to design and carry out this work. LBPs must do or supervise this work.

LBPs are registered and required to keep their skills and knowledge up to date. LBPs are licensed for the type of work they do. The licence classes include:

  • design
  • carpentry
  • roofing
  • brick and blocklaying
  • external plasterering
  • foundations
  • site.

Your choice of designer, builder or tradesperson is important as not all building practitioners are licensed. 

The rules about restricted building work are part of the council’s role in consenting and inspecting building work. This protects you and future owners by creating a record of who did what on your home and how it meets the Building Code.

Under the law, each LBP who works on your home must provide a Certificate of Design Work or Record of Building Work.

Work that is restricted

Restricted building work is residential design, construction or alteration work that:

  • requires a building consent
  • and involves or affects a home’s:
    • primary structure
    • weathertightness
    • certain fire safety design.

Generally, you’ll need to use LBPs for bigger, or more complex jobs.

Check if you need consents may help with your planning if your project is basic or considered ‘low risk’.

Only work that’s covered by one of the seven licence classes is restricted building work.

Work to your home’s primary structure

Any work or design that alters the primary structure of your home is restricted building work. This is work that contributes to the resistance of vertical and horizontal loads.

Examples of where primary structure building elements may be found
Foundations and subfloor framing Slab on ground, piles (including braces), foundation walls, strips, rafts, pads, jack studs, bearers, stringers
Floors Slabs, joists, trusses, composite flooring systems
Walls Studs, lintels, solid construction, piers
Roof Rafters, purlins, trusses
Columns and beams Columns, posts, pillars, beams
Bracing Cross bracing, sheet bracing, shear walls, diaphragms

Work to your home’s weathertightness

Work or design intended to keep water out or help control moisture within the building fabric is restricted building work.  It’s also called work to ‘external moisture management systems’.

Examples of external moisture management systemsAreas where these may be found

Damp-proofing

Floors in direct contact with ground moisture
Sub-floor/suspended floors and solid walls exposed to moisture in the air
And including damp-proofing protection

Roof/wall cladding and roof/wall cladding systems (attached to the outside of framed or solid walls or roofs)

Building wrap
Drained cavities
Cladding
Fixings
Windows, doors and skylights
Ventilators
Openings and penetrations
Flashings and seals
Joints and junctions
Surface treatments (eg waterproof coating)
Waterproofing (waterproof coatings)

Water-proofing

Waterproof coating to solid walls and roofs exposed to airborne moisture
Waterproof membranes to deck/balcony areas

Fire safety design

This only applies to small to medium sized apartments (which includes townhouses).   

Design work on fire safety systems must be done or supervised by an LBP with the correct licence class.  It ensures protections such as warning systems, escape routes and precautions against the spread of fire are included in the design.

Examples of fire safety systemsAreas where these may be found

Emergency warning systems

Automatic or manual emergency warning systems

Evacuation and fire service operation systems

Electromagnetic or automatic doors or windows
Emergency lighting systems
Fire service lift control
Escape routes
Final exits
Signs
Fire hose reels
Fire separations
Smoke separations
Refuge areas

Supression or control systems

Automatic systems for fire suppression
Mechanical or passive ventilation or air handling systems
Pressurisation systems
Smoke control systems
Dampers
Fire hose reels
Building hydrant systems
Fire separations smoke separations

Other parts of design

Interface with systems
Fire systems centre
Emergency power supply

Meaning of ‘residential’

The rules about restricted building work cover residential building work to a house or small to medium sized apartment.

A house is:

  • a free-standing, fully detached building consisting of a single residential unit.

A small to medium sized apartment is a building that:

  • contains two or more residential units (apartments or townhouses) or residential facilities (such as a foyer, laundry, garage, etc)
  • does not contain commercial units or facilities
  • has a maximum height of less than 10m (the vertical distance between the highest point of its roof – excluding aerials, chimneys, flagpoles and vents – and the lowest point of the ground).

Work that is not restricted

Work will not be ‘restricted building work’ if one or more of the following circumstances apply:

1. If the work is not to a house or small to medium sized apartment building. For example, work to the following buildings will not be restricted building work:

  • detached garages
  • carports
  • mixed use apartment (such as buildings with shops)
  • any commercial building of any height
  • any large apartment building (exceeding 10m in height)
  • installing a domestic wind turbine
  • installing a domestic swimming pool
  • installing a cable car to a home.

2. If your building work does not require a building consent. For example:

  • small carports
  • some demolition or removal work
  • repair and maintenance using comparable materials in the same position
  • alteration of some internal walls (non-structural)
  • installation of most windows.

Check if you need consents has more detailed information.

3. If your project does not affect or involve work to the primary structure of the building or its weathertightness. For example:

  • fitting new sanitary fixtures where there were not any previously (such as in new kitchen or ensuite)
  • installing a wood burner
  • installing other specified systems in small to medium apartments (such as smoke alarms or a lift)
  • installing insulation to external walls in a home.

4. Work that does not fit within one of the LBP licence classes. For example:

  • external tanking work
  • off-site manufacture of building components (such as pre-built frames and trusses)
  • manufacture design (such as design of a proprietary fire alarm system).

Note that all building work in New Zealand must meet the performance standards of the Building Code – whether or not it is restricted building work or requires a building consent.

If you’re unsure if your building work is restricted, a licensed designer should be able to help, or talk to your council.

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: