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 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 plastering
- 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 carries out restricted building work 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 | Piles (including braces), foundation walls, jack studs, bearers, stringers |
| Floors | Slabs, joists, composite flooring systems |
| Walls | Studs, lintels, solid construction, piers |
| Roof | Rafters, purlins, trusses |
| Columns and beams | Columns, posts, pillars, beams |
| Bracing | Metal strip or timber 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 systems | Areas where these may be found |
|---|---|
|
Damp-proofing |
Slab on ground |
|
Roof/wall cladding and roof/wall cladding systems (attached to the outside of framed or solid walls or roofs) |
Building wrap |
|
Water-proofing |
Waterproof coating to solid walls and roofs exposed to airborne moisture |
Fire safety design
This only applies to small to medium sized apartments including 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 systems | Areas 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 |
|
Supression or control systems |
Automatic systems for fire suppression |
|
Other parts of design |
Interface with systems |
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.