A fellow out in Hokowhitu emailed me last spring, pretty rattled. He’d built a tidy little deck and a sleeper retaining wall along the back of his Palmerston North section, and a neighbour had mentioned he “probably needed a consent for that.” Cue a weekend of panic.
I’m Grant Ellison, and I’ve spent the last nineteen years building decks, retaining walls and fences around Palmerston North – Hokowhitu, Awapuni, Milson, and out as far as Ashhurst – so I get some version of that phone call most months. The good news I gave him is the same thing I’ll tell you: a lot of ordinary outdoor work in New Zealand doesn’t need a building consent at all, because it falls under what’s called exempt or permitted work. The trouble is the line isn’t where most people guess, so it pays to know it before you start, not after the neighbour pipes up.
Where the consent line actually sits
Under the Building Act, most building work needs a consent unless it’s specifically exempted in Schedule 1. Councils across the country, Palmerston North City Council included, work off those same national rules, so the thresholds are identical whether you’re in Hokowhitu or Hataitai. The exemptions exist for low-risk jobs, but they come with conditions, and “low-risk” has a tighter meaning than most people expect. I always send clients to the government’s Building Performance site to read the actual clause before they start, rather than lean on what worked for a mate’s section.
What I can usually build without a consent
Most of the common backyard jobs around Palmerston North’s quarter-acre sections and newer subdivisions fall into this table, provided you stay inside the limits:
| Structure | Exempt if | Consent usually needed if |
|---|---|---|
| Deck or platform | Floor no more than 1.5m above ground | Floor higher than 1.5m |
| Retaining wall | 1.5m or under, no extra load on it | Over 1.5m, or holding up a driveway, building or another wall |
| Fence or garden wall | Up to 2.5m high | It also serves as a swimming or spa pool barrier |
| Shed or small single-storey building | Under 30 square metres, subject to conditions | Over 30 square metres, or it becomes habitable |
| Paths, paving, planting | Not classed as building work | N/A |
When I’m quoting a job that sits close to one of these numbers, landscaping contractors around Karori are usually the ones who flag it early, because they’ve seen a plan get redrawn once someone measures a retaining wall from the low side of a slope instead of the high side. Notice the pattern in that table: it’s always height, load or size. Cross one of those and you’re into consent territory.
The jobs that trip people up
Retaining walls and drainage catch out more Manawatū homeowners than anything else, because the 1.5 metre limit sounds generous until you’re standing on a sloping Hokowhitu or Aokautere section and the wall needs to hold back a driveway. On the “needs a consent” side of the ledger, I’m usually looking at:
- A deck more than 1.5 metres off the ground.
- A retaining wall over 1.5 metres, or one carrying a surcharge load like a driveway, house or another wall.
- Any fence or wall that doubles as a swimming or spa pool barrier.
- Plumbing and drainage tied into the wastewater system.
- A sleepout or similar that picks up power and water and starts looking like a habitable room.
If you’re weighing up a wall near a boundary, my piece on working near boundaries and the rules to know covers the setback side, which is a separate question from the consent one.
Exempt from consent isn’t exempt from the rules
This is the bit worth tattooing on the back of your hand. Even when work is exempt from a building consent, it still has to comply with the Building Code, and it may still need a resource consent under the district plan – especially near a boundary, on a flood-prone flat, or where a tree or heritage rule applies. Exempt only means the council doesn’t sign off the building work before you start; it doesn’t mean the footings or the drainage standards disappear. Get those wrong on an exempt deck and it’s still your problem, and your liability, later – the timber and screws are the cheap part, getting it right the first time is what actually costs.
Ring the council before you dig, not after
A quick call or email to Palmerston North City Council, or your own council, before you start costs nothing and can save thousands. Retrospective consent for work you’ve already built is slower and more expensive than doing it right the first time, and it can hold up a house sale later when the LIM report doesn’t match what’s sitting in the backyard. I tell every client to get the exemption confirmed in writing, so there’s a record sitting in an inbox somewhere. A screenshot of a tidy email beats a fuzzy memory when you’re selling in ten years’ time.
Questions I get asked on site
Does a deck need building consent in Palmerston North? Usually not, if the floor is no more than 1.5 metres above the ground – but a higher deck almost always does. Check the current thresholds on the Building Performance site or with the council before you build.
Do I need consent for a retaining wall? A retaining wall up to 1.5 metres high that isn’t carrying an extra load is usually exempt. A taller wall, or one holding up a driveway or building, generally needs a building consent – and on a sloping Manawatū section that height limit gets used up faster than people expect.
What does it cost to get this wrong? There’s no consent fee for exempt work, which is the appeal, but retrospective consent on work already in the ground typically costs more than an upfront application would have, plus the delay while the council decides whether to accept it.
If work is exempt, do I still have to follow the Building Code? Yes. Exempt work still has to meet the Building Code and may still need a resource consent under the district plan. Exempt only means the council doesn’t need to approve the building work in advance – the standards don’t go anywhere.