Installing a fence along a shared boundary on uneven ground is one of the more common fencing challenges NZ homeowners face, especially on hilly sections. With the right preparation, the correct technique for your terrain, and a clear conversation with your neighbour, it's a job many confident DIYers can tackle — though a qualified fencer will save you time and headaches on tricky sites.
Talk to Your Neighbour First
Before you dig a single hole, have a conversation with your neighbour. Under the Fencing Act 1978, both property owners generally share the cost of a sufficient fence on a common boundary. You're required to give your neighbour written notice (a fencing notice) before starting work, and they have the right to agree, object, or negotiate the style and cost. Skipping this step can lead to disputes and even legal action. If you can't reach agreement, the Disputes Tribunal can help resolve it.
Also check your title and survey plan to confirm the exact boundary location. Fencing on the wrong line — even by a small margin — can cause serious problems down the track. If you're unsure, a licensed cadastral surveyor can peg the boundary for you.
Do You Need a Building Consent?
In most cases, a standard residential boundary fence does not require a building consent under Schedule 1 of the Building Act 2004 — but there are exceptions. Fences over 2.5 metres in height, retaining walls over 1.5 metres, or fences near a watercourse may require consent. Always confirm with your local council before starting, as rules vary by district. You can find general guidance at MBIE Building Performance.
Choosing Your Method: Stepping vs Raking
On uneven ground, you have two main approaches to keeping your fence looking tidy:
Stepping (Stepped Fence)
- The fence panels remain level and horizontal, but drop in steps to follow the slope.
- Works well with pre-made panels (e.g. lapped timber or Colorsteel).
- Leaves triangular gaps at the base of each step — you may need to infill these with timber, concrete, or a gravel board if you want to keep animals in or out.
- Easier for a DIYer to build accurately.
Raking (Raked or Sloped Fence)
- The fence follows the slope continuously, with palings or boards cut at an angle to match the ground.
- Gives a cleaner, more seamless look with no gaps at the base.
- Requires more skill and careful measurement — each paling may need to be individually cut.
- Better suited to post-and-paling or feather-edge styles.
For most NZ residential sections with a moderate slope, stepping is the more practical DIY choice.
Setting Out Your Posts
Good posts are the foundation of any fence. Here's the general process:
- Mark the boundary line using a string line and pegs.
- Locate your posts — typically 1.8 m to 2.4 m apart, depending on your fence style and rail span.
- Dig your post holes — a general rule of thumb is to bury one-third of the total post length in the ground. For a 1.8 m fence, use a 2.7 m post and bury 900 mm. On soft or unstable ground, go deeper.
- Use a post-hole borer (available for hire at Bunnings or Mitre 10) to save time and effort.
- Set posts in concrete — a bagged rapid-set concrete mix is convenient. Keep posts plumb (vertical) using a spirit level and temporary bracing while the concrete cures.
- On a slope, set all posts to the finished height of the fence above ground level at each post location — not to a uniform height above sea level. Use your string line as a reference.
Timber and Material Selection
For NZ conditions, choose timber that is rated for ground contact where posts will be buried. Look for H5-treated timber for in-ground use and H3.2-treated for above-ground exterior use. Common NZ options include treated pine and macrocarpa. Check with your local PlaceMakers or timber merchant for what's available in your area.
For rails and palings, H3.2 treated pine is the standard. If you're using steel posts or Colorsteel panels, follow the manufacturer's installation instructions carefully.
Attaching Rails and Palings
- Fix horizontal rails to your posts first, keeping them level (for a stepped fence) or parallel to the slope (for a raked fence).
- Use galvanised or stainless steel fixings — never plain steel, which will rust and stain your timber in NZ's damp climate.
- Attach palings or boards to the rails, maintaining consistent spacing. A offcut of timber makes a handy spacer.
- For a stepped fence, cut the bottom of each paling to sit just above ground level at each step.
Boundary Fence Costs — A Rough Guide
| Fence Style | Approximate DIY Cost (per metre) | Approximate Installed Cost (per metre) |
|---|---|---|
| Post and paling (timber) | $80–$150 | $150–$280 |
| Lapped panel (timber) | $90–$160 | $160–$300 |
| Colorsteel/metal panel | $120–$200 | $200–$350 |
These are broad guides only — costs vary significantly by region, ground conditions, and material prices. Get at least two quotes from local fencers.
When to Call a Professional
Consider hiring a qualified fencer if:
- Your section has steep or unstable ground, rock, or high water tables.
- The fence is over 2 metres tall or involves retaining elements.
- You're unsure about the exact boundary location.
- The job involves concrete block or masonry fencing (which may also require an LBP — check at Licensed Building Practitioners).
- You simply want the job done efficiently and to a professional standard.
You can find experienced, local fencing contractors on tradedirectory.co.nz.
