Building consents are New Zealand's way of making sure new building work meets the Building Code. They're not optional for work that requires them — and doing consent-required work without one can cause real problems when you sell, insure, or renovate later.
Here's the practical guide to what does and doesn't need a consent.
Work that ALWAYS needs a building consent
- New buildings (houses, granny flats, garages over 10sqm)
- Structural alterations (removing or adding load-bearing walls)
- Additions (extensions, second-storey additions)
- Plumbing work (new bathrooms, kitchens, hot water cylinders, drainage)
- Electrical work that requires connection to the network
- Anything affecting weathertightness (recladding, re-roofing, window replacement that changes size)
- Decks more than 1.5m above ground, or attached to a habitable building
- Retaining walls over 1.5m high (or under load surcharge)
- Solid fuel fires (woodburners, fireplaces)
- Swimming pools and pool fencing
Work that USUALLY DOESN'T need a consent
- Cosmetic renovations (painting, tiling, replacing fittings)
- Replacing fittings like-for-like (taps, toilets, basins — as long as plumbing isn't modified)
- Like-for-like kitchen replacement (same layout)
- Ground-level decks under 1.5m high
- Outbuildings under 10sqm
- Most fences under 2.5m high
- Carports under specific size/height limits
- Internal non-structural wall removal (with caveats)
Building consent exemptions (Schedule 1)
New Zealand's Building Act Schedule 1 lists specific exemptions where work doesn't need a consent — but conditions apply. The exemptions cover things like:
- Garages and outbuildings under 30sqm (with conditions)
- Detached dwellings less than 30sqm where supervised by an LBP or chartered professional engineer
- Single-storey additions to detached houses under 30sqm
- Small standalone structures (pergolas, sheds) under thresholds
These exemptions are useful BUT they require the work to be done by a qualified person and to comply with the Building Code anyway — even though no consent is issued. The work still has to be code- compliant; you just don't need council pre-approval.
Resource consent — different from building consent
Don't confuse the two:
- Building consent — checks the work meets the Building Code (structural integrity, safety, weathertightness).
- Resource consent — checks the work complies with local district plan rules (zone restrictions, site coverage, height, density).
Most residential building work needs only a building consent. You only need a resource consent if you're doing something the district plan restricts in your zone — e.g. building closer to a boundary than permitted, exceeding height limits, or doing minor dwellings in a rural zone.
How long does a consent take?
The statutory timeframe for a residential building consent is 20 working days. In practice, most councils process in 25–45 working days because the clock pauses when they ask for more information.
Resource consents take longer — typically 8–16 weeks depending on whether the application is notified or non-notified.
What does a consent cost?
Building consent fees vary by council and project complexity but budget roughly:
- Simple consent (deck, garage, small alt): $1,500–$3,500
- Standard residential renovation: $3,500–$6,000
- New house: $6,000–$15,000+
Add development contributions on new builds (can be $10K–$30K depending on council and zone).
What happens if you do consent-required work without one?
It catches up with you eventually. Common consequences:
- Council enforcement (can require remedial work or removal of the structure)
- Insurance won't cover unconsented work damage
- When you sell, the unconsented work shows in a LIM report and can significantly reduce buyer interest or sale price
- When you renovate, you may have to retrospectively consent the earlier work before getting consent for the new
The honest summary
If in doubt, ask. Most councils have a free pre-application service where you can discuss whether your work needs a consent. A good builder will tell you at the first site visit which category your project falls into and what consenting is needed.
Finer Builds handles all council liaison and consent applications as part of the build — you don't have to deal with council unless you want to. Book Your Free Consultation for a straight answer on your specific project.