While not legally required under the Dividing Fences Act 1991 (NSW), getting a boundary survey before building a fence in Sydney is strongly recommended. In practice, many fence disputes start because neighbours assume the existing fence line is the legal boundary—when it often isn’t.
A boundary identification survey typically costs $800-$1,500 (inc GST) in Sydney and can prevent a mistake that costs $5,000-$20,000+ to fix once a fence is built in the wrong place.
Is a Boundary Survey Legally Required for a Fence?
No. The Dividing Fences Act sets out how neighbours share costs and how to give notice, but it doesn’t force you to obtain a survey. However, you are still responsible for ensuring the fence is constructed on the correct boundary and does not encroach onto the adjoining lot.
If you build on the wrong side, you may be required to remove the fence and restore the land. Disputes can escalate quickly, especially in tightly held suburbs where blocks are narrow (e.g., Inner West terraces, Eastern Suburbs semis, or Northern Beaches sloping lots).
Why Fences in Sydney Are Often Not on the True Boundary
Even if a fence has been there for decades, that doesn’t make it a legal boundary. Common reasons fences drift off line include:
- Old timber fences rebuilt “in the same spot” (but shifted slightly each time)
- Retaining walls and landscaping that push the practical fence line away from the boundary
- Missing or disturbed survey marks (pegs removed during renovations or driveway works)
- Assumptions based on online maps (which are not precise enough for construction)
- Older subdivisions where historical measurements and occupation don’t perfectly match modern evidence
How Much Does a Fence Survey Cost?
A boundary identification survey for fence purposes in Sydney typically costs $800 to $1,500. This is suited to locating existing corners and providing confidence for positioning a new dividing fence.
If marks are missing or the parcel is complex, you may need a full boundary re-establishment survey, usually $1,800-$3,500. Turnaround is commonly 5–10 business days depending on workload and the amount of plan research required through NSW Land Registry Services (LRS).
What Happens If Your Fence Is on the Wrong Boundary?
If your fence is built on the wrong side of the line, you may need to remove it and rebuild in the correct position—often after you’ve already paid for materials, labour, and demolition of the old fence.
Typical consequences include:
- Cost to remove and rebuild the fence ($3,000-$10,000+ depending on fence type)
- Neighbour claims for encroachment and loss of use of land
- Delays to other works (landscaping, retaining, driveway, pool, or extensions near the boundary)
- Legal costs if the dispute escalates
Can You Use Your Title Plan to Find Your Boundary?
Title plans, DP diagrams, and online mapping are useful for understanding the parcel generally, but they are not suitable for setting out a fence line on the ground. In NSW, boundaries are determined by an experienced surveyor interpreting evidence in accordance with legislation and survey practice, including the Surveying and Spatial Information Act 2002 (NSW) and the registered plan history held by NSW LRS.
Online maps can be out by 0.2m–1.0m+. On narrow lots, that’s the difference between a compliant fence and an expensive problem.
Practical Steps Before You Build a Fence (Sydney Checklist)
Before you call a fencer, consider the following steps:
- Talk to your neighbour early and agree on the fence type, height, and cost split.
- Serve a fencing notice as required by the Dividing Fences Act if you’re seeking contribution.
- Check for easements along the boundary (drainage, sewer, services). These may appear on a DP and can be supported by a Section 88B instrument under the Conveyancing Act 1919.
- Book a boundary identification survey if there’s any doubt about the line.
- Confirm access—tight side passages and strata driveways can affect where and how the fence is constructed.
Do Councils Require a Survey for a Fence?
Many Sydney councils don’t require a survey for a standard dividing fence, but council rules may apply for front fences, corner lots, heritage areas, or fences over certain heights. Requirements differ across council areas such as the City of Sydney, Inner West Council, Bayside Council, Northern Beaches Council, and Sutherland Shire.
If you’re combining a fence with other works (retaining walls, driveways, pools), you may be in a DA or CDC pathway under the Environmental Planning and Assessment Act 1979—and accurate boundary information becomes even more important.
FAQ
How accurate is a boundary identification survey for a fence?
It is designed to locate and interpret the legal boundary using available evidence and existing survey marks. If marks are missing or evidence conflicts, a full re-establishment may be recommended for higher certainty.
Can my neighbour stop me from building a fence?
A neighbour can object to cost sharing or fence type/height, but the Dividing Fences Act provides a process for resolving disputes. A survey helps remove argument about the location of the line.
What if the existing fence is not on the boundary?
This is common. You can agree with your neighbour to rebuild on the true boundary, or keep the fence where it is by agreement. If there is an encroachment issue, get professional advice.
Do I need a survey if I’m just replacing an old fence?
If you’re rebuilding in the same location and there’s no dispute, you may choose not to survey. However, if you want the fence on the true boundary (or you suspect the old fence is off line), a survey is strongly recommended.
How do I book a boundary survey in Sydney?
Contact Sydney Surveyor Solutions (17 John Street, Mascot NSW 2020, (02) 5114 2551). Provide your address and, if possible, your Lot/DP details for faster research.
