Thinking about a reno? Let’s tackle the most googled question in Aotearoa: what renovations need a building consent?
So, What Work Needs Building Consent?
According to MBIE and councils like Auckland and Tauranga, you’ll definitely need a building consent when your project involves:
- Structural changes – additions, removing or altering load-bearing walls, re-piling, major earthworks Sonder Architectswellington.govt.nz+
12Building.govt.nz+12Sonder Architects+12 - Plumbing & drainage – adding new sanitary fixtures (e.g. fresh toilet or shower) Tauranga City Council+4Building.govt.nz+4Auc
kland Council+4 - Heating/air systems – installing woodburners or air-con systems Building.govt.nz+1Tauranga City Council+1
- Retaining walls – higher than 1.5 m (3 m rural), unless engineered Tauranga City Council+2Building.govt.nz+2wel
lington.govt.nz+2 - Fences and walls – over 2.5 m tall wellington.govt.nz+3Building.
govt.nz+3Tauranga City Council+3 - Decks & platforms – more than 1.5 m above ground Building.govt.nz
- Sheds and sleepouts – over 30 m², or between 10–30 m² without lightweight/exempt design Building.govt.nz+1Superior Renovations+1
- Pools & spas – any new or replaced pools/spas require consent and barriers Building.govt.nz+6Auckland Council+6canibuildit.govt.nz+6
- Alterations to specified systems – e.g. fire alarms, exit signage, sprinklers Tauranga City Council+7Building.govt.nz+7wel
lington.govt.nz+7
What About Work That Doesn’t Need Consent?
Under Schedule 1 of the Building Act and recent MBIE reforms, some lower-risk projects aren’t consented, especially if done by a Licensed Building Practitioner or professional engineer Auckland Council+9Building.govt.nz+9Tau
- Ground-level patios and shade sails (if built to spec)
- Garden sheds under 30 m², low decks <1.5 m high Auckland Council+1Christchurch City Council+1Building.govt.nz+2Tau
ranga City Council+2Sonder Architects+2 - Minor interior work — non-load-bearing walls in homes
- Small plumbing repairs or replacing existing fixtures Auckland Council+1Sonder Architects+1
Even if it’s exempt, the work must still follow the Building Code, and you may need a licensed pro to carry out or supervise chesters.co.nz.
Spotlight: Kitchen & Bathroom Renos
Fair dinkum tricky turf.
- Consent required for adding new plumbing fixtures (like a new ensuite), installing tiled wet areas or waterproof membranes Auckland Council+1Sonder Architects+1
- Consent NOT needed for relocating a sink, vanity or replacing existing fixtures—so long as it’s still a single sanitary fixture and done by an authorised person Auckland Council+1Sonder Architects+1
Why It Matters
- Council consent ensures the work meets the Building Code for safety, durability, fire and structural standards chesters.co.nz+2Sonder Architects+2Sonder Architects+2.
- Doing consented work protects your insurance, and can save you from fines (up to $200 k) and being forced to undo non-compliant work Tauranga City Council+2Building.govt.nz+2Son
der Architects+2. - And buyers love a property with proper records—consented work adds value and gives peace of mind.
Quick Reference Table
| Renovation Type | Consent Needed? | Notes |
|---|---|---|
| Structural changes |  Yes |
Walls, foundations, re-piling, earthworks |
| Decks/platforms >1.5 m | Yes |
|
| Retaining walls >1.5 m | Yes |
(3 m in rural, unless designed by engineer) |
| Fences >2.5 m height | Yes |
|
| Pools & spas | Yes |
Includes safety barriers |
| Woodburner or air-con install | Yes |
|
| Sheds >30 m² | Yes |
10–30 m² may need LBP oversight |
| Plumbing: new sanitary fixture | Yes |
eg. new toilet/shower |
| Kitchen/bathroom move of existing sink |  No |
If it’s just replacing or moving without adding |
| Exempt low‑risk work | No |
e.g. small patios, maintenance, small sheds |
What To Do Next
- Check your renovation against the list.
- Use the MBIE tool “Can I Build it” at canibuildit.govt.nz Auckland CouncilSonder Architects+10Building.govt.nz+
10Sonder Architects+10Sonder Architects+2Tauranga City Council+2Building.govt.nz+2wel lington.govt.nz+8Auckland Council+8Building.govt.nz+8Son der Architects+1Christchurch City Council+1Tauranga City Council+2canibuildit.govt.nz+2 Building.govt.nz+2 - Chat with your council or a licensed building practitioner if unsure.
- Get a consent early—don’t wait till after the joists are in.
RB THOMAS LTD Advice
Don’t wing it—getting the right consent is crucial. We’ll help you scope the job, work out if compliance is needed, prep the application, and ensure your reno goes smoothly—no last‑minute hold‑ups or nasty surprises.
