Understanding these rights is one of the easiest ways to add space quickly and cost-effectively. At Kev Construct we build within these rules every week across Edgware, Barnet, Enfield and Harrow, so here is what you can usually do.
What counts as permitted development?
Permitted development is a set of rules that allow certain building work without applying to the council. The idea is to let homeowners make reasonable improvements without a lengthy process. The rights apply to houses, not flats or maisonettes, and they are reduced for listed buildings and homes in conservation areas.
The key point is that the work must stay within the published limits on depth, height and coverage. Go beyond them, even slightly, and you move into needing planning permission.
What can you build under permitted development?
As a general guide, the following are often possible under permitted development, subject to the current limits and your specific property:
- A single-storey rear extension within the allowed depth
- A rear extension no higher than four metres to the ridge in many cases
- An extension that does not extend beyond the side of the original house
- Outbuildings, garden rooms and garages within the rules
- Certain loft conversions within volume allowances
Because the exact limits change and depend on whether you have a terraced, semi-detached or detached home, we always recommend confirming the numbers before you start. A Lawful Development Certificate from the council gives you proof that the work is permitted.
Where do permitted development rights not apply?
There are important exceptions. You will normally need planning permission, not permitted development, if any of these apply:
- Your home is a flat or maisonette
- Your home is listed
- You live in a conservation area, national park or other protected area
- Permitted development rights have been removed by an Article 4 direction
- The project exceeds the size, height or coverage limits
Some newer estates also have permitted development rights removed as a planning condition, so it is always worth checking your address with the council.
What are the size limits in simple terms?
Here is a simplified guide. Always confirm the current figures for your property, as these are indicative only.
Meeting these limits is only half the job. The build still has to satisfy building regulations for structure, insulation and drainage, and the Party Wall Act may apply if you build near a shared boundary. We handle all of this as part of a proper build, and our Checkatrade rating of 9.67/10 from verified reviews reflects that care.
Frequently asked questions
Can I build an extension without planning permission?
Often yes, if it fits within permitted development limits. Single-storey rear extensions within the depth and height rules commonly qualify, but always confirm for your property.
How deep can a permitted development extension be?
As a guide, around 3 metres for a semi or terraced house and around 4 metres for a detached house, subject to current rules. Larger builds usually need planning permission.
Do conservation areas allow permitted development?
Rights are restricted in conservation areas, so many extensions there need planning permission. Check your address with the council before you plan.
Thinking about a permitted development extension? See our full house extensions service and request a free estimate. We will tell you honestly whether your project fits within permitted development or needs a planning application.
