What Is Cadastral Surveying in South Africa?

Cadastral surveying is the branch of land surveying that defines, records and maps the legal boundaries of land. In South Africa, every registered erf, farm portion, sectional title scheme and agricultural holding owes its existence to a cadastral survey. It is the precise, measured framework that says exactly where one property ends and the next begins, and why your property has a fixed size, defined corners and an exact shape on an official diagram.

This guide explains what cadastral surveying is, who carries it out, how the national cadastre underpins secure boundaries, and where the well-known SG diagram fits into the picture.

What does "cadastral" actually mean?

The word "cadastre" refers to a comprehensive, official register of land within a country. A cadastral survey establishes the legal extent of a parcel of land for registration purposes. It differs from other types of surveying you might have heard of:

• Cadastral surveying fixes the legal boundaries of a property: its beacons, dimensions and total extent.
• Topographical surveying maps the physical features of the land, such as contours, rivers and buildings.
• Engineering surveying sets out construction works like roads, dams and pipelines.

Cadastral surveying is the one that matters for registration. It produces the measurements that allow a property to be registered in the deeds office as a distinct, defensible parcel of land.

Who carries out cadastral surveys?

In South Africa, cadastral surveys may only be performed by a registered Professional Land Surveyor. Cadastral work is a regulated, signed-off profession precisely because the results carry legal weight.

When a surveyor subdivides a farm, creates a new township, consolidates two erven or pegs out a sectional title scheme, they locate the boundary corners on the ground, place beacons (the survey pegs), measure the distances and bearings between them, and calculate the area enclosed. They then capture all of this on a survey diagram and submit it for official examination and approval.

The Surveyor General system and the national cadastre

South Africa runs a Surveyor General system. Each surveyor's work is checked and approved by a Surveyor General office before it becomes part of the official record. This examination step is what gives the cadastre its reliability: a diagram is not merely the surveyor's say-so, it has been independently verified against neighbouring surveys.

Once approved, the survey becomes part of the national cadastre, the master record of all surveyed land in the country. Every new survey must tie into the surveys around it, so the cadastre grows as a single, seamless, interlocking map. This is why two neighbouring properties share an exact common boundary rather than overlapping or leaving a gap.

The Surveyor General and the deeds office are two separate institutions doing two separate jobs. The Surveyor General governs the survey, shape and extent of land. The deeds office governs ownership, transfers and bonds. They work hand in hand, but they are not the same thing.

Where the SG diagram fits in

The most visible output of a cadastral survey is the SG diagram, named because it is approved by the Surveyor General. An SG diagram is the survey of your specific property. It records:

• The boundary corner beacons (pegs) and how they are marked;
• The length and bearing of every boundary line;
• The total extent, or size, of the property in square metres or hectares;
• Any servitudes, such as a right of way or a municipal pipeline, that cross the land.

This is the document people are really after when they want to confirm where their boundary runs, how big their stand is, or whether a servitude affects their plans for a wall, pool or extension.

SG diagram versus title deed

This is the distinction most property owners get wrong. The SG diagram is the survey: boundaries, beacons, dimensions and extent. The title deed is the ownership record: who owns the property and what bonds are registered against it. Two different documents, held by two different offices, answering two different questions.

If your question is "where exactly are my boundaries and how big is my property?", you need the SG diagram, and a cadastral survey is what created it. If your question is "who owns this property and is there a bond on it?", you are in deeds territory, and you can look that up using DeedsCheck.

How to find the SG diagram for a property

You do not need to commission a new survey to see the cadastral diagram that already exists for a registered property. Most erven, farms and agricultural holdings already have approved SG diagrams on record from when they were originally surveyed.

The quickest way to check is to run a free SGCheck search. Search by address on the map, or by erf number plus town and portion, and you will see for free which SG diagrams exist for that property. Erf properties are treated as urban, while farms and agricultural holdings are rural. From there you can retrieve and download every diagram on the property as a single PDF for a flat R230 fee. Sectional title properties, such as flats and townhouses, are sourced manually on request rather than instantly.

Cadastral surveying is the quiet system that keeps every property boundary in South Africa secure and certain, and the SG diagram is your window into it.

Frequently asked questions

Is a cadastral survey the same as an SG diagram?

Not quite. The cadastral survey is the process of measuring and defining a property's boundaries, while the SG diagram is the approved document that results from it. The diagram is the record you read and download; the survey is the work behind it.

Who is allowed to do a cadastral survey in South Africa?

Only a registered Professional Land Surveyor may perform a cadastral survey. Their work is then examined and approved through the Surveyor General system before it joins the official cadastre, which gives the diagram its legal standing.

Does cadastral surveying tell me who owns a property?

No. Cadastral surveying deals with boundaries, beacons, dimensions and extent, not ownership. To find out who owns a property and whether a bond is registered against it, use a deeds search such as DeedsCheck.

How do I find the existing cadastral diagram for my property?

Run a free SGCheck search by address or by erf number, town and portion. You will see at no cost which SG diagrams exist for the property, then pay a single R230 fee to retrieve and download them all as a PDF.