Floor area ratio, coverage and height restrictions explained with examples

Three numbers decide how much building an erf can carry: floor area ratio, coverage and height. They appear in every land use scheme, on every zoning certificate, and in every architect's first conversation with a client. They are simple once explained, and expensive to misunderstand.

Coverage: how much ground you may cover

Coverage is the percentage of the erf that may be covered by buildings, measured as the area under roof when seen from above.

On an erf of 1,000 m² with an illustrative coverage limit of 50%, buildings may cover up to 500 m² of ground.

Points that trip people up:

• It is footprint, not floor area. A double-storey house with a 200 m² footprint uses 200 m² of coverage, not 400 m².
• Roofed structures usually count. Garages, carports and covered patios generally add to coverage. This is why so many properties drift over their limit one small addition at a time.
• It can vary with height. Some schemes allow more coverage for a single-storey building than for two or three storeys.

Floor area ratio: how much floor you may build

Floor area ratio, or FAR, is the total floor area of all storeys divided by the area of the erf.

Permitted floor area = erf area × FAR

On a 1,000 m² erf:

• an FAR of 0.4 allows 400 m² of floor area;
• an FAR of 1.2 allows 1,200 m²;
• an FAR of 2.0 allows 2,000 m².

FAR is the control that most directly determines the value of development land, because floor area is what gets sold or let.

Schemes define what counts as floor area. Certain spaces are typically excluded — parking areas, for example — and the exclusions make a real difference to a design. Always read the definition in the scheme, not a rule of thumb.

Height restrictions

Height is normally controlled through a height zone, expressed as a maximum number of storeys, sometimes with a height in metres as well.

Height interacts with the other two controls. Your floor area has to be arranged within the coverage (the footprint) and the height (the number of floors).

How the three work together

The controls are applied together, and the tightest one wins.

Example. An erf of 2,000 m² with illustrative controls of 50% coverage, FAR 1.0 and three storeys.

• Coverage allows a footprint of 1,000 m².
• Three storeys on that footprint would be 3,000 m².
• FAR allows only 2,000 m².

FAR is the binding control. You could build 2,000 m² as two full floors, or as three floors of about 667 m² each, leaving more open ground.

Change the FAR to 2.0 and the picture reverses. FAR would allow 4,000 m², but coverage and height together allow only 3,000 m². Now height and coverage are binding.

Working out which control binds is the heart of a first-pass development assessment.

From floor area to "how many units can I build"

For residential development, floor area is one of several tests. To estimate how many units you can build:

1. Density test. Erf area in hectares × permitted units per hectare.
2. Floor area test. Permitted floor area ÷ average unit size, after allowing for passages, stairs and other common areas.
3. Parking test. Whether the required bays physically fit.
4. Site test. What remains after building lines, servitudes and unusable land are taken off.

The smallest number is the realistic one. The full method is in what can I build on my property.

Coverage and height restrictions on a house

For a homeowner planning an extension, the same controls apply on a smaller scale.

• Adding a second storey uses floor area and height, but no extra coverage.
• Extending outwards uses coverage and floor area.
• Adding a carport or covered patio uses coverage.

If you are close to your coverage limit, building up may be the only option. If you are in a low height zone, building out may be.

Before briefing an architect, find out what applies to your erf and roughly how much has been used already. Aerial imagery helps with the second part: see reading aerial imagery history.

What these controls do not include

Building lines. Even within your coverage, you may not build inside the building lines. See building lines.

Servitudes. No building over a registered servitude without the holder's agreement.

Title conditions. A deed can impose its own limits.

Parking and open space. Both take ground that might otherwise carry building.

The theoretical maximum from coverage, FAR and height is an upper bound. The buildable reality is usually less.

Getting the figures for an erf

The controls for a particular erf come from the land use scheme, the zones that apply to the erf's location, and any conditions specific to the erf. Do not assume the figures from a neighbouring property or a general table.

The Development potential report on checkproperty.co.za sets out the zoning, density, height and parking zones and the building lines for the erf. Where the rules for that zone have been verified, it also gives coverage and permitted uses and an assessment of second-dwelling and subdivision potential.

Asking for more

If the controls do not allow what you need, the scheme and by-law provide for applications to relax or amend them — for example, permission to exceed coverage, or a rezoning to change the FAR and height. These are discretionary and take time. See rezoning cost.

Frequently asked questions

Is FAR the same as coverage? No. Coverage limits the footprint. FAR limits total floor area across all storeys.

Does a basement count towards floor area? It depends on the scheme's definition and on what the basement is used for.

Does a swimming pool count as coverage? An open pool is not a roofed building, but check the scheme's definition.

The bottom line

Coverage limits the ground you cover, floor area ratio limits the floor you build, and height limits how you stack it. Work out which one binds on your erf, then subtract the land you cannot build on.

Check the zoning for a property.

This is general information, not town-planning or architectural advice. The figures used are illustrative; the controls for any erf must be confirmed from the land use scheme.