Coverage, Floor Area, and FSI Explained — What Every Property Owner Needs to Know

https://youtu.be/o9sdb4KF7Yk

If you’re planning to build, extend, or develop a property in South Africa, you’ve probably come across terms like coverage, floor area, and FSI in your dealings with the local authority. Whether you’re in Cape Town, George, Nelson Mandela Bay, or dealing with your local municipality, they’ll ask you about these figures — and getting them wrong can delay or derail your project.

Here’s a simple breakdown of what each term means.

Coverage: How Much of Your Site Are You Building On?

Coverage refers to the footprint of your building — in other words, how much of your site is physically covered by the structure when you look at it from above.

Let’s say you have a 1,000 m² site and your building covers 500 m² of it. Your coverage is 50%.

This matters because your zoning scheme sets a maximum coverage limit for your property. It also dictates your building lines (how close to the boundary you can build) and what the property can be used for. Exceed the coverage limit and your plans won’t be approved.

Floor Area: The Total Space Across All Storeys

Floor area is different from coverage because it accounts for every level of the building. If your 500 m² footprint has two storeys, your total floor area is 1,000 m². Coverage stays the same — the building still only covers 500 m² of the ground — but the floor area doubles.

This is why multi-storey buildings can provide significantly more usable space without necessarily exceeding coverage limits.

FSI: Floor Space Index

FSI stands for Floor Space Index, and it’s the ratio that controls the maximum total floor area you’re allowed to build on a given site.

The formula is simple:

Maximum Floor Area = Site Area × FSI

So if you have a 1,000 m² site with an FSI of 2, you’re permitted to build up to 2,000 m² of floor space in total. You can find your property’s FSI in your zoning certificate or by submitting a town planning inquiry to your local municipality.

FSI is particularly useful on multi-storey developments, where you want to maximise the building’s potential without exceeding what the zoning allows.

A Quick Summary

TermWhat It Measures
CoverageThe building’s footprint as a % of the site
Floor AreaTotal built space across all storeys
FSIThe multiplier that sets your maximum floor area

Need Help Working Out Your Numbers?

If you’re unsure what your property’s zoning allows — or you just want a quick calculation before you start planning — get in touch with us. We work through these figures every day and can give you a clear picture of what’s achievable on your site.

How to Determine the Age of a Building (When You Don’t Have Approved Plans)

If you’re an architect or built environment professional working on a heritage permit — or even a routine building plan submission — you’ll need to know whether the building you’re working on is older than 60 years.

Why does it matter? Because under the National Heritage Act, any building older than 60 years (or any site on which such a building stands) is protected. That means you need to declare the building’s age in your plans, and getting it wrong has real consequences.

The Obvious Starting Point: Approved Plans

Approved municipal plans are your best source. They’ll tell you when a building was constructed. If you can get them, go to the municipality and request the approved plans on record — that’s your most reliable evidence.

But what if there are no approved plans? That’s where it gets trickier, and where many practitioners get stuck.

The Fallback: The Survey Diagram and General Plan Number

If approved plans aren’t available, look at the survey diagram for the property. The survey diagram records when the land was first surveyed, and crucially, it contains a General Plan number — which tells you when that township or subdivision was established.

For example, a General Plan dated 1983 tells you the land was subdivided in 1983. That gives you a definitive earliest possible date for any buildings on it.

This is a document you can attach to your heritage permit application or building plan submission as supporting evidence of age.

An Important Nuance

The General Plan date tells you when the land was subdivided — not necessarily when the building was constructed. A General Plan from 1984, for instance, doesn’t mean the building was built that year. Construction may have followed a decade later.

That’s why the survey diagram works best as a floor — it establishes the earliest the building could have been built. Pair it with approved plans wherever possible to narrow it down further.

In Summary

SourceWhat it tells you
Approved municipal plansActual construction date — most reliable
Survey diagram / General Plan numberDate the land was subdivided — useful fallback

When approved plans aren’t on record, the survey diagram is a legitimate and useful document to support your application. Know where to find it, and keep it in your toolkit.

The Easy-Peasy Guttering System: Rainwater Harvesting with a 75mm Downpipe

I want to show you a very simple guttering system — an easy-peasy guttering system you can do really quickly when you’re working with corrugated iron.

Why is this important? Because people are sometimes too fast to leave projects, to let somebody else take over — to let somebody else take our freedom away from us by telling us it’s too complicated. It isn’t.

The Idea

The whole system is built around a simple 75mm PVC downpipe — the standard kind you’ll get at any Builders Warehouse or Home Depot, along with the little elbows to match.

The trick is this: you split a length of downpipe down the side, then open it up and clip it onto the end of the roof sheet, where it acts as a gutter. The corrugated iron edge sits inside the split pipe, and the rainwater running off the roof feeds straight into it.

I’m not the guy who thought this up — I’ve seen other guys do it before, including a very good friend of mine who has used it on very nice buildings.

The Tools

Nothing fancy: a pair of gloves, a cordless hand drill (mine’s a 14-volt), a crosscut saw, and a level — I like to use a Stanley.

I cut the slit on a table saw, but you don’t need one — you can do it with a handsaw. One warning: be careful of the sharp edges of the corrugated iron. I don’t want to create any accidents with this.

Putting It Together

Split the pipe, open it up, and work it onto the edge of the roof sheet — I prefer feeding the thick end on first. At the corner, an unsplit elbow clamps over the split section, which also helps grip the gutter more firmly around the sheet. Then secure it in place with a screw from your hand drill — that’s all you need to hold the downpipe in position. Do that at each corner and you’re away.

At the bottom end, the downpipe runs into a 200-litre drum — ours was rescued from a dump site; it used to belong to Castrol, but now it belongs to Pebble Spring Farm. From the drum, a few attachments let us run the water off to feed the chickens and the rabbits.

It’s really that easy.

Do the Numbers

Don’t be confused by the size of this very little project — it’s a rabbit hutch and a chicken coop we built here. But the maths is worth looking at.

This little piece of roof is 1 metre wide by 1.5 metres — 3 square metres of roof sheet in total. Here in Port Elizabeth, at 34 degrees south near the coast, we get about 600 to 700mm of rain per year. Over 3 square metres, that’s around 2 kilolitres of water a year — an average of about 5 or 6 litres a day.

The chickens and rabbits are not going to use 5 litres a day. This little unit becomes completely self-sustaining — and the whole system is going to expand to 10, 15, 20 units.

Keep It Small, Keep It Free

Don’t try this on big industrial operations. I’m talking about home projects — a little shed, a little house, a little cottage, a chicken coop, that kind of stuff.

Tell me how it works for you in your environment. We’re looking for easy things, we’re looking for cheap things, we’re looking for stuff you can do yourself — to set yourself free.

Yes, You Need a Permit to Demolish a Building Too

Almost everybody knows that before you build something, you have to get a permit. You’ve got to get plans approved, you’ve got to get the zoning in place. But not everybody knows that before you demolish something, you also need a permit.

Where to Get the Application

If you’re in Nelson Mandela Bay, the demolition application form is available online — go to nelsonmandelabay.gov.za and download it. Make sure you’re getting the latest version.

If you don’t have internet access, you can go to the building inspectorate on the fourth floor, in the building opposite the info centre — near where Treasury is, by the Lillian Diedericks building. But honestly, the easiest route is just to get it off the website.

What You Need to Submit

The application comes with a checklist, and it can all be emailed in. You’ll need:

An aerial photograph of the building to be demolished, a locality map, and elevations of the building to be demolished.

And here’s the important one: if the building is older than 60 years, you need a heritage permit before you submit — that’s an application to the provincial heritage authority, ECPHRA. That’s a whole process on its own (we’ll cover it separately). If the building is younger than 60 years, you don’t need one.

You’ll also need to provide proof of age of the building. Don’t be tempted to claim a building is younger than 60 years when it isn’t — that’s fraud, and you can get into serious trouble. I’m not exaggerating when I say jail time is a possibility.

What It Costs

It’s a flat fee — currently R641 — payable to the municipality. They’ll confirm the amount and give you payment details when you submit.

The Bottom Line

That’s the paperwork and the approvals you need in place before you demolish anything. So don’t say you didn’t know — because now I’ve told you.

It’s really not that complicated, but if you need help with this, look us up. And if you’re not in Nelson Mandela Bay, don’t think this doesn’t apply to you — every jurisdiction in South Africa has a similar process. Wherever you are in the country, you’re going to need a demolition permit.

Experience First, Build Second: My Advice on Developing Short-Stay Accommodation

People often come to my office asking for technical advice about developing short-stay accommodation. The questions are always the same: How do the land use rights work with the zoning? What may I or may I not do? How would the structure work? How do the foundations work? How does the drainage system handle stormwater, or get the toilets to flush?

All valid questions. But if you’re thinking of developing short-stay accommodation on your place — let’s say you’ve got a farm or some land — my advice is something different.

Be a Guest Before You Become a Host

Experience these places. As many as you can. As a visitor, as a user.

Try the five-star ones. Try sleeping under the stars. I’ve stayed in all kinds of accommodation — I’ve slept under the stars on the bank of a river, and I’ve slept in five-star hotels in Berlin. Each of those can be a great experience, because a great experience is about measuring expectation against the product — against the thing itself.

So visit as many places as you can, from the five-star right down to sleeping next to a river and everything in between, and measure your experience of each. When you then develop your own short-stay accommodation, tweak it. Add the little things. Maybe it’s something as small as a tea bag, or a box of matches to light a fire. Maybe it’s something big. But if you focus in on the experiential side, you’ll find yourself working on what’s achievable rather than dwelling on what’s lacking.

A Case in Point: Where We Stayed Last Night

The place we stayed in last night may not be for everybody — and to their credit, they advertise quite clearly on the website exactly what it is.

It’s a homebuilt structure. A bed, a double bunk behind it, a rudimentary little table, a small fireplace inside. Outside, there’s a bathroom with a shower — hot and cold water — a little basin, and a beautiful outdoor tub.

Could it be more five-star? Sure. Did I have fun having a bubble bath out in the open under the stars last night? Yes, I did.

That’s the point. Experience the rustic, the glitzy, the glamorous and the unglamorous. Out of all of it, you’ll begin to get a feel for the kind of user experience you want to offer your own guests.

The technical stuff is a dime a dozen — you can buy that in. What you can’t buy in is your own personal understanding of what you, as a human being, would want. Align your product with that, and you’re set.

The Architect’s Eye: How the Place Is Put Together

Of course, I can’t switch off the technical eye entirely. For those interested, here’s how the structure works:

The floor is OSB. The cabinets and joinery are made from decking planks. The walls are a combination of corrugated iron and hessian — hessian for the ceilings — with Flexite (a fibre cement board) along some walls. The windows are rescued steel frames, including French door windows, with light fittings from Builders Warehouse. The steps are decking board, though the plank spacing is wrong — too bouncy. External cladding is cut-off pine end strips. The roof is a very simple mono-pitch, which leaked inside last night — I don’t know why. The whole structure sits on gum poles set into a concrete pad. I don’t like that detail; it’s going to rot. There’s foam filling the gaps, and the ground level is too high in places.

None of that is meant unkindly. It’s a homebuilt place that delivers exactly the experience it promises — and that’s the lesson.

The Takeaway

Get out there and experience these places. That’s what matters. The technical knowledge can be bought in, but the feel for what makes a stay memorable — that has to come from you.