Restricted building work (RBW) is a category of building work in New Zealand that must be carried out or directly supervised by a Licensed Building Practitioner (LBP). The rules exist to protect homeowners by ensuring that the most critical, structural, and weathertight parts of a home are built to a safe and compliant standard.
What Is Restricted Building Work?
Restricted building work covers building work that affects the structural integrity or weathertightness of a residential building — the parts that, if done poorly, could make a home unsafe or cause serious long-term damage like leaking or collapse.
Under the Building Act 2004, RBW applies to residential buildings of up to three storeys. It does not generally apply to commercial buildings (which have separate requirements).
The types of work classified as RBW include:
- Structural work — foundations, framing, load-bearing walls, beams, and connections designed to NZS 3604 (Timber-framed buildings) or by a structural engineer
- Weathertightness work — external cladding, roofing, windows, and doors that form part of the building envelope
- Design work — producing design plans for the above categories of work
- Site work — earthworks and drainage that directly affect the building's structural performance
If you're unsure whether a specific project falls under RBW, check with your local council or visit MBIE Building Performance for detailed guidance.
Who Is a Licensed Building Practitioner?
An LBP is a tradesperson who has been assessed and licensed by MBIE to carry out or supervise restricted building work. There are several licence classes, each covering a different area of work:
| LBP Licence Class | Covers |
|---|---|
| Carpentry | Structural framing, roofing, cladding |
| Design | Residential building design |
| External Plastering | Plaster-based cladding systems |
| Bricklaying & Blocklaying | Masonry walls and structures |
| Roofing | Roof coverings and weathertightness |
| Site | Overall site management and supervision |
You can search for and verify an LBP's licence on the Licensed Building Practitioners register. Always check that the person you hire holds a current, appropriate licence class for the work being done.
Why Does This Matter for Homeowners?
If restricted building work is carried out by someone who is not licensed, several serious consequences can follow:
- The work may not comply with the NZ Building Code, meaning your council could require it to be redone
- You may struggle to sell your home or make an insurance claim if unlicensed work is discovered
- The unlicensed person can face fines of up to $20,000 under the Building Act
- You, as the homeowner, may also face penalties if you knowingly allowed unlicensed work
LBPs are also required to provide you with a Record of Work on completion, confirming what restricted building work they carried out. Keep this document safe — it's an important part of your home's building history.
Does Restricted Building Work Need a Building Consent?
Most restricted building work will also require a building consent from your local council before work begins. There are some exemptions under Schedule 1 of the Building Act (for example, certain minor repairs and maintenance), but these exemptions are specific and sometimes misunderstood.
Always confirm with your local council whether your project needs a consent before starting. Even if work is exempt from consent, it must still comply with the NZ Building Code, and if it's RBW, it still needs to be done by an LBP.
BRANZ is a useful independent resource for understanding building standards and best practice in New Zealand.
What Can a Homeowner Do Themselves?
Homeowners can carry out some building work on their own home without being an LBP, provided the work is not restricted building work and does not require a building consent (or falls under a Schedule 1 exemption). Examples of work homeowners can typically do themselves include:
- Painting and decorating
- Basic garden landscaping (not affecting drainage or structure)
- Installing shelving or non-structural fittings
- Replacing like-for-like interior linings (in some cases)
However, do not assume work is exempt or unrestricted without checking. When in doubt, contact your council.
Safety note: Even for work that doesn't require an LBP, always follow safe work practices. For guidance on health and safety on building sites, visit WorkSafe NZ.
Electrical, Plumbing, and Gas Work
It's worth noting that electrical, plumbing, gasfitting, and drainlaying work is governed by separate legislation and licensing systems — not the LBP scheme. These trades have their own restricted work categories:
- Electrical work must be done by a registered electrician — see EWRB
- Plumbing, gasfitting, and drainlaying must be done by a licensed practitioner — see PGDB
Never attempt restricted electrical or plumbing work yourself — the risks include fire, electrocution, gas explosion, and flooding.
When to Call a Professional
You should engage a qualified LBP any time your project involves:
- New construction or major alterations to a home
- Changes to load-bearing walls, rooflines, or foundations
- Re-cladding or reroofing
- New windows or doors that affect weathertightness
- Any work requiring a building consent
A good LBP will help you understand the consent process, work to the NZ Building Code, and provide you with the required Record of Work. You can find qualified, local builders and LBPs on tradedirectory.co.nz.
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