Boundary walls and building lines: the rules explained

Building lines and boundary walls cause more disagreements between neighbours than almost anything else in residential building. Knowing the rules before you design saves time, money and friendships.

What is a building line?

A building line is a line set back from a property boundary, inside which buildings must be kept. There are usually three types:

• Street building line: the distance buildings must be set back from the street boundary
• Side building lines: the distance from the side boundaries
• Rear building line: the distance from the back boundary

The distances depend on the zoning of your property under the City of Cape Town’s Development Management Scheme, and sometimes on the height of the building. On many single residential properties, garages and outbuildings can be built closer to the boundary than the main house, within limits.

Your title deed may also contain building lines that are stricter than the zoning scheme, and these must be complied with too.

Common rules of thumb

For many single residential properties, the street building line is a few metres and the side and rear building lines are smaller, but there are many exceptions: corner plots, small erven, older townships, special areas and properties with title deed conditions. Never assume. Your architect should confirm the actual building lines for your property before design starts.

Boundary walls

Boundary walls and fences have their own rules:

• Height. Free-standing boundary walls are generally limited in height. Higher walls need specific approval.
• Street walls. Walls on the street boundary are often subject to additional design rules, especially in heritage areas, where solid high walls may not be allowed.
• Plans. A low free-standing wall may fall under minor building work, but a wall that retains soil, is above the height limits or is in a heritage area generally needs plans. Check before building.
• Visibility at driveways. Walls near driveways and intersections may need to allow visibility for traffic.

Shared boundary walls

A wall built exactly on the boundary belongs to both neighbours. Repairs, painting and replacement should be agreed between you. Before demolishing or building on a shared boundary, talk to your neighbour and put agreements in writing.

Building closer than the rules allow

If your design needs to encroach over a building line or exceed a height limit, you can apply for a departure under the City’s planning by-law. This is a separate application from the building plans. Neighbours are usually notified and may comment or object. If they support the application, their written consent can make the process faster.

Departure applications take time. Plan for this, or design within the rules if the timeline is tight.

Talk to your neighbours early

Most disputes start because a neighbour sees a structure going up without warning. Telling them about your plans early, and showing them the drawings, avoids most problems. A neighbour’s support also helps if you need a departure.

If you are planning a project close to your boundary, talk to us. We can help you understand what is possible before you commit to a design.