What is restricted building work in NZ?
Short answer
Restricted building work (RBW) is work critical to a home's structure or weathertightness — plus the design of fire safety systems in multi-unit buildings. By law it must be designed, carried out or supervised by a Licensed Building Practitioner, who provides a Certificate of Design Work or a Record of Building Work.
Key facts
- Covers structural and weathertightness work on homes
- Applies to houses and residential buildings under 10m high
- Must be done or supervised by a Licensed Building Practitioner
- Comes with documentation — keep the Certificate / Record of Building Work
What counts as RBW
RBW is the work that keeps a home structurally sound and dry — the primary structure and the external moisture management — and the design of fire safety systems in multi-unit buildings. It applies to residential buildings of any height up to small-to-medium apartment buildings under 10 metres.
Why it matters
These are the areas where failures are most expensive and dangerous — leaky buildings, structural defects. Requiring an LBP is how the system tries to keep accountability on the critical work.
Records you should get
When an LBP does or supervises RBW, they must provide a Certificate of Design Work (for the consent application) or a Record of Building Work (for the code compliance certificate). Keep these — you'll want them for resale and insurance.
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Related questions
Sources: Building Performance (building.govt.nz) — restricted building work; LBP (lbp.govt.nz). General information for NZ homeowners, not legal advice — building rules change and vary by council, so confirm critical details on the official source before acting. Last updated 2026-05.