Sometimes. That is the honest answer, and the reason it cannot be improved on in a sentence is that the decision turns on your specific property rather than on the extension you want to build.
Two identical rear extensions, on two identical houses, a mile apart in Norfolk, can have different answers. One needs a full planning application. The other does not need permission at all. The difference is not in the design — it is in what has already happened to the house, where it sits, and what the deeds and the planning history say.
This article explains what actually decides it, and in particular the things that quietly remove the rights people assume they have.
Permitted development, honestly described
There is a national set of rights, granted by government rather than by your council, that allows certain building work to go ahead without a planning application. These are permitted development rights, and a great deal of ordinary domestic work falls within them.
Two things are worth understanding before you rely on that.
The rights are narrower than most people believe. They come with a long list of conditions covering position on the plot, height, roof form, materials, what you may do to the front of a house, and what you may put on a boundary. A scheme that breaches any one of those conditions is not partly permitted development — it needs full planning permission.
We deliberately do not publish the current limits here. They have changed more than once in recent years and a stale figure on a page like this would be actively harmful. The dimensions and thresholds must be checked against the current government technical guidance for householders on the day you rely on them, and checked against your particular property. Any article that quotes you a depth in metres without telling you when it was last reviewed should be treated with caution.
The principle to work from is this: permitted development is a set of narrow, conditional allowances, not a general right to build a reasonable extension.
What removes your permitted development rights
This is the part that catches people, and it is where an afternoon of checking saves months.
Listed status. Rights are substantially restricted, and separate listed building consent is required for works affecting the character of the building. See our article on extending a listed building.
Conservation areas. Norfolk has a large number of them — in Norwich, in the market towns, and in a great many villages across South Norfolk, Broadland and North Norfolk. Inside one, several categories of permitted development are removed or reduced, particularly at the side and on anything visible from the street.
Designated landscapes. The Broads and the nationally designated coastal landscape in north Norfolk carry tighter restrictions than ordinary land. If you are in the Broads executive area, note that the Broads Authority is your planning authority, not the district council, and it has its own local plan.
Article 4 directions. A local authority can withdraw specific permitted development rights across a defined area — a village, a street, sometimes a single estate. There is no way to guess where these apply. You have to check with the authority.
Flats and maisonettes. Householder permitted development rights apply to houses. They do not apply to flats or maisonettes at all.
The allowance already being used up. This is the one that produces the most unpleasant surprises. Permitted development allowances are calculated against the original house — as it was built, or as it stood at a fixed historical date — not as you bought it. If a previous owner added a conservatory in 1998 and a utility room in 2006, some or all of the allowance may already be spent, and the previous owner's work does not have to be visible from the road for that to be true.
Planning conditions on newer estates. The single most commonly missed item. When a residential development is granted permission, the authority frequently attaches a condition removing permitted development rights across the whole site, so that the estate keeps a consistent character and so that garden space is not lost. Buy a house built in the last few decades and there is a real chance it has no permitted development rights at all, despite looking exactly like the sort of house that would. Nothing about the property tells you. The information sits in the original planning decision for the estate, which is public and searchable.
Restrictive covenants. Not a planning matter, but worth naming here because it bites at the same moment. A covenant on your title can prevent building work regardless of what the planning system permits, and it is enforced privately rather than by the council. Check your deeds.
Norfolk specifics
Norfolk is not one planning environment. The property's address determines which authority decides your application and which local plan applies:
- Norwich City Council — the city, with a substantial conservation area coverage
- South Norfolk Council — Cringleford, Poringland, Stoke Holy Cross, Colton and the villages south of the city
- Broadland District Council — Thorpe End, Strumpshaw and the north and east of the city
- North Norfolk District Council, Great Yarmouth Borough Council, Breckland Council, King's Lynn and West Norfolk
- The Broads Authority — the executive area of the Broads, in its own right
- East Suffolk Council and Ipswich Borough Council for our Suffolk work
National permitted development rules are the same everywhere. What differs is the local plan applied to a full application, how conservation areas are drawn, where Article 4 directions apply, and the emphasis a particular authority places on issues such as parking, drainage or landscape impact.
Prior approval: the middle ground
Between "no permission needed" and "full planning application" there is a third route for certain larger single-storey rear extensions. It is not a full application, but it is not silence either. You notify the authority, adjoining neighbours are consulted, and if a neighbour objects the authority decides whether the impact on amenity is acceptable.
The thresholds and the process must be checked against the current guidance, as they have been amended. What is worth knowing in principle is that this route exists, that it takes weeks rather than days, and that a neighbour's objection genuinely can stop it.
Why we recommend a certificate of lawfulness anyway
If your extension falls within permitted development you do not need permission. You can simply build it.
We still recommend applying for a lawful development certificate. It is a formal confirmation from the authority that what you propose, or what you have built, is lawful.
The reason is the sale of the house, three or eight years from now. A conveyancing solicitor acting for your buyer will ask what authorisation exists for the extension. "It was permitted development" is an assertion. A certificate is evidence. Without one, the usual outcome is a delay while indemnity insurance is arranged, a price renegotiation, or in the worst case a buyer who walks away. The certificate costs a fraction of what that disruption costs, and it is far easier to obtain before the work than after it.
It also does something useful now: it forces someone to check the position properly rather than assume it.
Two Norfolk examples
A porch extension at Thorpe End, on the eastern edge of Norwich, is at the modest end of what we do. Porches sit in their own part of the permitted development regime, with their own conditions on size, height and proximity to the highway — a small project can still fall the wrong side of a condition.
The rear extensions at Cringleford, in South Norfolk, are the more common case: a family house where the ground floor no longer works, extended to the rear. Cringleford has both older property and a lot of recent development, which is precisely the mix where the answer to "do I need permission" depends entirely on which house you are standing in front of.
A checklist to run before you spend anything
Work through this in order. All of it is free.
- Is the building listed? Search the National Heritage List for England.
- Are you in a conservation area? Check your local authority's map.
- Which authority is yours — district council, or the Broads Authority.
- Is there an Article 4 direction covering your property. Ask the authority.
- Search the planning history of your address and your estate. Look for conditions removing permitted development rights, and for extensions already built.
- Read your title deeds for restrictive covenants.
- Check the flood zone on the Environment Agency maps.
- Then, and only then, start designing.
Almost every expensive planning surprise we see would have been caught at step five.
What to do next
If the answer is that you need permission, that is not bad news. It means the scheme is assessed on its merits, and a well-argued application on a reasonable site usually succeeds. For smaller applications planning approval may take eight to ten weeks; for larger applications this could be thirteen to fifteen weeks, and it is sometimes delayed. That period runs from the date the authority validates the application — after the fee is paid and the required documents are present — not from the date you submit it.
Our house extensions service covers design and delivery, and our planning applications service covers the submission and the negotiation that follows.
The initial consultation is free, it happens at the property, and constraints are the first thing we look at. We will review the site, discuss what you want to achieve, identify the planning and technical challenges, and outline next steps and indicative timelines.
Call +44 (0) 1508 830 310, email info@archidite.com, or book a free initial consultation.
Last reviewed: July 2026. Permitted development rights are amended from time to time. Check the current government technical guidance for householders, and the position for your specific property, before relying on any general guidance.