Reviewed: 12 August 2026. Measuring an existing fence is not the same as establishing a legal cadastral boundary.
A tape, laser or aerial map can estimate fence length for budgeting. If the legal line is uncertain, disputed or important to new construction, use title/survey evidence and a licensed cadastral surveyor. The current fence may sit on the boundary, near it or wholly on one property.
Two different workflows
| Purpose | Suitable method | Output |
|---|---|---|
| Budget the existing run | Tape/laser and run schedule | Approximate lineal metres, gates, corners and access |
| Locate a new undisputed line from reliable pegs | Confirm records/marks and professional advice as needed | Set-out information appropriate to risk |
| Resolve missing pegs or disagreement | Licensed cadastral surveyor | Professional boundary definition/reinstatement |
What title diagrams can and cannot do
LINZ guidance explains that parcel boundaries can be right lines, arcs or irregular lines and are represented in cadastral survey datasets. A title diagram provides legal survey information; it is not always a DIY set-out plan. Old marks, occupation and source surveys may need professional interpretation.
Record physical evidence without moving it
- Photograph visible survey marks and their context.
- Record walls, fences, retaining and changes in alignment.
- Mark services, easements, rights of way and access constraints from available records.
- Do not disturb survey marks or represent an app/GPS overlay as a cadastral survey.
Why certainty can save more than it costs
Installing posts over the line can create encroachment and removal disputes. A boundary correction after concrete cures is more expensive than resolving material uncertainty first. Section 8 of the Fencing Act addresses fence encroachment without consent or court authority.
Once the line is established, switch to the run measurement method and fence length calculator. For neighbour notices and contribution, use the separate boundary fence rules.
Authoritative reference: LINZ cadastral boundary guidance.
What you can establish yourself
You can measure the physical fence, mark approximate working dimensions and compare obvious occupation features with plans. You cannot establish a disputed legal boundary merely by finding an online parcel line, old peg, retaining edge or existing fence. Cadastral boundaries are defined through survey evidence and legal records.
Use the right evidence level
| Purpose | Proportionate evidence |
|---|---|
| Early budget on an undisputed existing line | Measured fence length, photographs and clear assumption |
| Replacing like for like with neighbour agreement | Written agreement plus available title/survey information |
| New fence near a suspected boundary | Survey records and professional advice where position matters |
| Encroachment or neighbour dispute | Licensed cadastral surveyor and legal advice as appropriate |
| Fence beside retaining/building | Boundary evidence plus structural/planning checks |
Physical site-measurement method
- Sketch each straight run and label corners A, B, C and so on.
- Measure fence-face length and every gate opening separately.
- Record offsets to stable visible features without treating them as legal monuments.
- Photograph posts, pegs or marks but do not move or recreate them.
- Note changes of level, retaining and places where occupation differs from the plan.
Why online maps are not set-out tools
Council and LINZ map viewers are useful for identifying parcels and records, but displayed lines can be generalised or offset from aerial imagery. Phone GPS and consumer measuring apps are not cadastral instruments. Use them to organise a site visit, not to place a permanent boundary fence where centimetres matter.
From boundary certainty to construction length
Once the line is agreed or professionally defined, use How to Measure Fence Length to convert it into runs, openings, corners and allowances. For shared work, keep the boundary evidence with the written fence agreement and quotations.
Boundary authority: Land Information New Zealand cadastral survey guidance. A licensed cadastral surveyor should resolve material boundary uncertainty.