One of the most common sources of confusion in building plan submissions is floor area measurement. When you submit drawings to a municipality, you’re required to show your calculations — erf size, coverage, floor space ratio, and so on. But where do those definitions actually come from? This is something we get asked about regularly, so it’s worth setting the record straight.
Use the Definitions in Your Zoning Scheme
The first place you should be looking is your local zoning scheme. Not your own judgment, not a rule of thumb you picked up somewhere — the zoning scheme for the area where the project is located. If you’re working in Mossel Bay, use the Mossel Bay zoning scheme. George, use George’s. Nelson Mandela Bay, use ours. Each municipality publishes its own scheme, and the definitions for terms like “floor area”, “coverage”, and “floor space ratio” are contained in there. That is the authoritative source for submissions to that municipality.
This matters because the definitions are not universal. What counts as floor area in one scheme may be treated differently in another, and if you submit calculations based on your own interpretation rather than the relevant scheme, you’re going to run into problems.
The National Building Regulations Are Also Relevant
The second reference you should know about is SANS 10400 — the National Building Regulations. There is a section dealing with dimensions and measurement definitions that is worth familiarising yourself with. We’ll make a dedicated video on that part of the regulations, but for now, know that it exists and that it’s another legitimate source of definitions you can draw on.
For Retail and Commercial Projects: SAPOA
If you’re working on a shopping centre, commercial development, or any project where you’ll be providing floor area information to tenants or property owners, the relevant standard is published by SAPOA — the South African Property Owners Association. Their measurement standard is widely used in the commercial property industry, and if a landlord or tenant is asking for GLA or GBA figures, that’s the framework they’ll be working from.
Don’t Invent Your Own Method
This is the point we want to land firmly: don’t make up your own way of measuring things. It sounds obvious, but it happens more often than it should. The moment you start making ad hoc decisions — do I include the wall thickness or not? Does the deck count? How do I handle a double-volume void? Do I count the staircase on both floors? — you’ve left the realm of a defensible, document-backed calculation and entered territory that a municipal plan examiner can legitimately query or reject.
These are genuinely complex questions. The answers vary depending on which definition applies. The only way to get it right is to anchor every calculation to a specific clause in a specific document. When you do that, you have a basis to stand on. When you don’t, you’re exposed.
So to summarise: for municipal submissions, go to your zoning scheme first. Cross-reference with SANS 10400 where relevant. For commercial property work, use the SAPOA standard. Always work from the document — not from memory, not from habit, and not from a colleague’s interpretation of what seems reasonable.
If you’re unsure which definition applies in a specific case, ask. It’s a much shorter conversation before submission than after.
— Tim Hewitt-Coleman
Director, noh Architects
Gqeberha, Eastern Cape
noh ARCHITECTS 