You Could Unwittingly Be Gifting $100,000 to Your Neighbour with Bad Property Lines

Published on

12 Oct 2026

Property lines are not always where you think they are. A fence, driveway or garden edge might look like the dividing line between two properties, but it does not necessarily establish the legal boundary.

This can be particularly relevant for older properties where historical subdivisions, survey records and physical boundary markers may not align with what you see on the ground. A difference of just one metre might sound insignificant, but across a large block, that small discrepancy can add up to a surprisingly large area of land.

How much land could a one metre discrepancy cost you?

Imagine you own a 1,000m² block measuring 50 metres by 20 metres. If the boundary is one metre short along the 50-metre side, the missing strip would be:

50m × 1m = 50m

That is 50 square metres of land that you may not be using or have access to.

If the same one-metre discrepancy occurred along the 20-metre side, the difference would be 20m² instead.

The amount of land involved, therefore, depends on the dimensions and location of the discrepancy.

What could 50m² of land be worth?

The potential value of that missing land can vary dramatically depending on where you live. To demonstrate this, we looked at vacant land sales in 2026 across various SEQ suburbs.

In Mount Gravatt East, a 405m² block sold for $865,000, equivalent to roughly $2,136 per square metre. At that rate, 50m² represents more than $106,000 in land value.

In Banya on the Sunshine Coast, a 498m² block recently sold for $715,000, or approximately $1,436 per square metre. That puts 50m² at about $72,000.

Meanwhile, a 603m² vacant block in Lawnton sold for $775,000, equating to around $1,285 per square metre and approximately $64,000 for 50m².

In Kilcoy, a 608m² residential block sold for $375,000, which works out to about $617 per square metre. In Kingaroy, a 600m² vacant block sold for $235,000, or approximately $392 per square metre. In those examples, 50m² equates to roughly $31,000 and $20,000 respectively.

Of course, these calculations are only a guide. Land does not necessarily have a simple dollar-per-square-metre value, and factors such as zoning, location, access and development potential can significantly affect what an individual piece of land is worth. But the point stands – inaccurate property boundaries could be costing you.

Why property lines matter when you are building

The financial value is only part of the issue. If your property lines are not where you think they are, a one metre discrepancy could affect what you can actually do with your land.

Planning an extension? Building a shed? Installing a pool? Adding a retaining wall or creating access down the side of the house? Losing a strip of land could affect your plans, create major setbacks and impact your available space. It can also create problems if a fence or structure has been positioned incorrectly.

Queensland Government guidance states that property boundaries are established through cadastral surveying evidence and survey marks, rather than simply relying on fences, kerbs or GPS points.

Could your neighbour be getting your land?

You might never notice a boundary discrepancy until you need to use that part of your property. By then, the fence may have been there for decades, and everyone simply assumes it’s in the right place.

If you’re planning work near a boundary, buying or selling property, replacing a fence or simply want to know exactly where your land ends, a property boundary survey can establish the position of the legal boundary using historical records and actual field measurements. It’s a relatively small step that could uncover a much bigger issue.