Check a property boundary: using a property boundary map in Johannesburg

Most people have never seen the legal boundary of their own property. They have seen a wall, a fence or a hedge, and assumed it sits on the line. Usually it is close. Sometimes it is not, and the difference only comes out when someone wants to build, sell or subdivide.

A property boundary map lets you check a property boundary in a couple of minutes. This guide explains how, what the map can and cannot tell you, and what to do when something looks wrong.

Cadastral map Johannesburg: what a property boundary map is

A property boundary map draws the surveyed outlines of land parcels over a base map or aerial photograph. The technical name is a cadastral map: the cadastre is the official record of land parcels and their boundaries.

The cadastral map of Johannesburg shows every erf in every township, each with its number. Laid over aerial imagery, it shows at a glance how the legal parcels relate to the buildings, walls and roads on the ground. Search for "erf map Johannesburg" and this is what you are looking for.

How to check property boundary lines: a property boundary search

1. Go to checkproperty.co.za and type the address or the erf number and township.
2. Select the property. Its boundary is drawn on the map.
3. Switch between the map and aerial views to compare the outline with what is on the ground.

For a wider view — the erven around a property, or a whole street — the layer map shows boundaries across an area with planning and risk layers over them. It is included with a monthly plan.

If you only have an address, the search resolves it to the erf for you; see erf number lookup.

Five things to check on the map

1. Is it the right erf?

Confirm the erf number and township match your documents. On a street of similar houses it is easy to select a neighbour.

2. Does the shape match the fences?

Compare the outline with the walls and fences visible in the aerial image. Look for places where a wall is clearly inside or outside the line.

3. Does everything you were shown fall inside?

Garden, driveway, garage, pool, the strip down the side. Features that fall outside the boundary are not part of the property, whatever the seller believes.

4. Does anything of the neighbour's fall inside?

A neighbour's garage wall, carport or outbuilding sitting over the line is an encroachment onto the land you are buying.

5. How do structures sit against the boundary?

Buildings hard against a side boundary, or close to the street, raise a building line question. See also unapproved structures.

Common things a boundary map reveals

The "extra" strip. A previous owner fenced in a piece of the road reserve, a servitude area or a neighbour's land. It looks like part of the garden and is not.

The pavement garden. Lawn and planting between the wall and the kerb belong to the road reserve.

Panhandles. A long driveway that turns out to be a strip of the erf — or a servitude over someone else's.

Two erven sold as one. A house and its garden may straddle two separate erven. Both need to be in the sale agreement.

The opposite. An advert describing more land than the erf contains, because the measurement included a neighbouring vacant piece.

How accurate is a boundary map?

This matters, so plainly: an online boundary map is indicative.

The outlines come from cadastral data that has been positioned on a map, and the aerial image beneath has its own positional error. The two can be offset from each other by a noticeable margin, and from the true position on the ground. An apparent encroachment of half a metre on screen may be nothing more than image alignment.

Use the map for:

• identifying the erf;
• understanding its shape and size;
• spotting gross discrepancies — a structure several metres over a line;
• deciding whether a closer look is needed.

Do not use it for:

• deciding exactly where to build a wall;
• measuring a building line to the centimetre;
• settling a dispute with a neighbour.

For those you need the survey diagram and a land surveyor.

From the map to the diagram

The legal definition of the boundary is the survey diagram or general plan approved by the Surveyor-General. It gives each side's length and the position of each corner beacon. See SG diagram search.

A useful sequence:

1. Map — orientation and a first check.
2. Diagram — the dimensions and area on record.
3. Tape measure — a rough comparison of wall lengths with diagram lengths.
4. Land surveyor — relocation of the beacons where there is doubt.

When to get a land surveyor

• before building a boundary wall or any structure near a boundary;
• when the fenced area clearly differs from the diagram;
• when buying a property where boundary structures matter to the value;
• before subdividing. See can I subdivide my property;
• when a neighbour disputes the line.

Only a registered professional land surveyor can place or replace beacons. Their beacon certificate is what settles the matter.

Boundaries, erf size and value

The boundary defines the area, and area drives value — particularly for development, where yield is calculated from the registered extent. A fence that encloses 1,100 m² does not turn a 1,000 m² erf into a larger one. Always use the registered size. See erf size lookup.

Encroachments: what if the wall is in the wrong place?

Options, depending on the facts:

• Leave it, where the difference is trivial and both neighbours are content — recognising that it may come up at a later sale.
• Move the structure to the true boundary.
• Regularise it by agreement, through a registered servitude or a boundary adjustment involving a surveyor and a conveyancer.

Long-standing occupation can in some circumstances give rise to legal claims, which is a question for an attorney. Get advice before removing anything or signing anything.

Frequently asked questions

Is the boundary on Google Maps accurate? Consumer maps are not a cadastral record. Use a cadastral boundary map, and the survey diagram for anything that matters.

Who owns a boundary wall? That depends on where it stands and how it was built. A wall on the common boundary is generally shared.

Can I find the beacons myself? Sometimes they are visible as iron pegs. Often they are buried or lost, and a surveyor will need to relocate them.

The bottom line

A property boundary map answers "which land is this, and does it match what I am looking at?" in minutes. Treat it as a first check, go to the survey diagram for the record, and call a surveyor when the position on the ground matters.

Search a property to see its boundary.

This is general information, not legal or surveying advice. Boundaries shown on maps are indicative; consult a professional land surveyor to locate a boundary on the ground.