Building lines explained: how close to the boundary can you build?

Ask an architect what stops a design fitting on an erf and the answer is often not the size of the land. It is the building lines. They quietly remove a strip of your property from use, and they are behind a large share of neighbour disputes, refused plans and unpleasant surprises at sale.

What a building line is

A building line is an imaginary line set at a fixed distance inside a boundary of the erf. Between that line and the boundary, building is restricted. The space in between is the building restriction area.

There are two main kinds:

• Street building lines, measured from the boundary with the street.
• Side and rear building lines, measured from the boundaries shared with neighbours — sometimes called side and rear spaces.

A typical erf has a street building line of several metres and smaller side and rear lines. The distances depend on the zoning, the erf and the road it fronts.

Where building lines come from

This is the part most people miss: a single erf can be subject to building lines from more than one source.

The land use scheme. The scheme sets building lines for each zone, often varying with erf size or the number of storeys.

The title deed. Many older townships have building lines written into the conditions of title. These can be wider than the scheme's.

Road legislation. Erven along provincial and national roads are subject to building restrictions under roads legislation.

Approved conditions. A rezoning or subdivision approval may have set specific building lines for the erf.

Where more than one applies, you must comply with all of them, which in practice means the most restrictive. A relaxation of the scheme building line does not remove one in the title deed.

Why building lines exist

• Light, air and privacy between neighbouring buildings.
• Fire safety — distance between buildings limits fire spread.
• Road widening and services — street building lines keep space clear for future road improvements and for services.
• Streetscape — a consistent setback gives a street its character.
• Sight lines — particularly on corners and at driveways.

What may be built inside a building line

The building restriction area is not always completely off-limits. Schemes commonly allow certain things within it, or allow them with permission — boundary walls and fences, and in some cases minor structures. The specifics are in the scheme and differ between street and side boundaries.

The general position for anything substantial — a room, a garage, a cottage — is that it needs to respect the line or have a relaxation.

Finding the building lines for your erf

1. Check the zoning and scheme provisions. A zoning check is the start. The Development potential report on checkproperty.co.za sets out the building lines that apply to the erf.
2. Read the title deed. Look for conditions that refer to building lines or to distances from boundaries. See title conditions.
3. Check for servitudes. A servitude along a boundary acts like a building line and is often stricter. See survey diagrams and servitudes.
4. Look at the approved building plans. They show the building lines that were applied when the plans were passed.
5. Confirm where the boundary really is. A building line is measured from the boundary, so a fence in the wrong place puts everything else in the wrong place. See check a property boundary.

Building line relaxation

If you need to build inside a building line, you apply for a relaxation.

For a scheme building line, this is an application to the municipality. Expect to provide a motivation, a site plan showing the encroachment, and the written comments or consent of affected neighbours. The municipality considers the effect on neighbours, the street and services.

For a title deed building line, a municipal relaxation is not enough. The condition itself must be dealt with, through the process for removing or amending restrictive title conditions. That is a larger exercise, often run together with other applications.

For a road authority building line, the relevant roads authority must agree.

Relaxation is discretionary. Encroachments that affect a neighbour's privacy or light, or that sit over services, are the ones most likely to be refused.

Building lines when buying

Building line problems are among the commonest defects found during a sale.

• A garage or cottage built up against the boundary with no relaxation on record.
• A carport in the street building restriction area.
• A neighbour's structure encroaching on the erf you are buying.

Any of these can delay transfer or become your problem afterwards. Before you offer:

• compare the boundary on the map with the structures visible in aerial imagery;
• ask for approved plans for every structure, including outbuildings;
• ask whether relaxations were obtained and ask to see them.

More on this in unapproved structures: what a buyer inherits.

Building lines and development yield

For developers, building lines directly reduce buildable area. On a small or narrow erf the effect is dramatic: take several metres off the front and a couple off each side and rear, and the remaining envelope may be a fraction of the erf.

This is why a yield based only on coverage and floor area ratio can be badly optimistic. Draw the building lines first, then see what fits.

Frequently asked questions

Can I build a boundary wall on the building line? Boundary walls are generally treated differently from buildings, with their own height limits. Check the scheme and any estate or title rules.

My neighbour built over the building line. What can I do? Start by checking whether they have a relaxation. If not, the matter can be raised with the municipality's building control or planning enforcement.

Do building lines apply to a second storey? Yes, and some schemes set a larger side space for upper storeys.

The bottom line

Building lines come from the scheme, the title deed and sometimes road law, and you must satisfy all of them. Find them before you design, and check them before you buy.

Look up a property to see what applies to the erf.

This is general information, not town-planning or legal advice. Building lines for a specific erf must be confirmed from the land use scheme, the title deed and the municipality.