Granny Flat Rules in Cape Town: What the Zoning Scheme Allows

On most Single Residential properties in Cape Town, you can build a granny flat without a rezoning or consent application. The City calls it a "second dwelling", and it's an additional use right in Single Residential Zoning 1 (SR1). You still need approved building plans, and the flat has to meet the zoning scheme's rules on size, height and building lines. Those rules were updated on 1 October 2025, which also brought in two new options: a smaller "supplementary dwelling unit" for staff or family, and "affordable rental flats" in certain areas. A lot of granny flat advice online still predates that, and some of it quotes size limits that aren't in the scheme at all.

What Counts as a Granny Flat in Cape Town

The City of Cape Town's Development Management Scheme defines a second dwelling as another dwelling unit on a property where a dwelling house is allowed. It can be:

It's a full dwelling unit, with its own kitchen, bathroom and entrance. That's what separates it from an extra bedroom or a home office.

Do You Need Permission to Build a Granny Flat?

Not from the planning side, if your property is zoned SR1 and the flat meets the scheme's rules. A second dwelling is an additional use right, so there's no rezoning, consent use or neighbour approval process. But you do need:

If the flat breaks a development rule, such as building lines or height, you'll need a departure application on top of the plans.

Granny Flat Size and Height Rules

There's no fixed 60 m² or 120 m² cap for a second dwelling in the City's scheme, despite what some guides say. The real limit is set by the main house's size and by how much floor space, coverage and building-line room is left on your plot.

Building Lines and Windows Facing the Neighbours

A granny flat has to sit within the property's building lines, which depend on the size of the plot. Smaller plots can build closer to the side boundaries. Two rules catch a lot of people:

That's why the corner of the garden that looks perfect for a granny flat often turns out to need a departure, or a different layout with no windows on the boundary side.

Can You Convert a Garage Into a Granny Flat?

Often, but not always as-is. Garages and outbuildings are allowed right up against a side boundary, because the scheme treats them differently from homes. Once a garage becomes a dwelling, it's no longer an outbuilding. The scheme says an outbuilding may not be used for people to live in. So a converted garage has to meet the dwelling rules. A garage built on the boundary with a new window facing the neighbour usually won't comply without a departure. Converting it also needs building plans, because you're changing its use.

Supplementary Dwelling Units: The New 50 m² Option

Since October 2025, SR1 properties can also have a supplementary dwelling unit as an additional use right. It replaced what used to be called domestic staff quarters, and it's tightly limited:

If you want a unit to rent out, a second dwelling is the right route. A supplementary unit suits a parent, an adult child or live-in staff.

Affordable Rental Flats and Third Dwellings

The 2025 changes also introduced affordable rental flats: a building of two or more rental units, allowed as of right only in areas the City has mapped for them. They can't be built on a property that already has a second dwelling, third dwelling or supplementary unit, so it's one route or the other. The scheme also provides for a third dwelling on some properties, where a main house and a second dwelling already exist. Whether either applies to your property depends on its zoning and location. A town planner or the City's district office can confirm it.

Can You Sell or Subdivide a Granny Flat?

Building a second dwelling doesn't give you a right to subdivide the property. The scheme states that the existence of a second dwelling is not in itself a reason to approve a subdivision. Owners who want to sell units separately usually look at sectional title instead, which is its own legal process.

Planning a Granny Flat That Works

The planning rules decide where a granny flat can go. The build decides whether it's worth living in: a proper foundation, damp-proofing and drainage around the new walls, and a roof and finishes that match the main house. Building on the side or rear of an existing house is very similar to a home extension, and the same questions come up about ground levels, existing drains and access for materials. Whether the flat is separate or attached, it needs approved plans, and our guide to council approval in Cape Town explains how that process works.

Getting Your Granny Flat Built

SmartCurve has been building granny flats, home extensions and additions across Cape Town since 2017, on more than 100 completed projects. Call us before you commission plans: on a free site visit, we'll look at your plot, your existing house and where a new unit could realistically go, before any quote is written. Your plans are drawn by an architect or draughtsperson and approved by the City. We then build from those approved plans, with one team handling the brickwork, plastering, tiling, plumbing and painting. Like our home extensions in Cape Town, every granny flat we build is quoted at a fixed price, with no hidden costs. Book your free site visit or call us on +27 62 907 0802.