London refused 22.0% of larger householder extension prior approvals in the first quarter of 2026. But nobody applies in ‘London’: Enfield refused 4 of 68, Barnet 25 of 56. Your postcode moves the odds more than your drawing does, and it is worth knowing which side of that you are on before you pay a fee.
Across the 33 boroughs, 1,017 larger householder extension prior approvals were decided between January and March 2026 and 224 were refused, a rate of 22.0%. The borough spread is much wider than that average: Enfield refused 4 of 68 decisions, while Barnet refused 25 of 56. Your postcode moves the odds more than your drawing does.
| Borough | Decided | Refused | Refusal rate | Homes that are houses |
|---|---|---|---|---|
| Enfield | 68 | 4 | 5.9% | 58.8% |
| Redbridge | 98 | 18 | 18.4% | 64.1% |
| Harrow | 121 | 29 | 24.0% | 61.6% |
| Ealing | 57 | 19 | 33.3% | 45.2% |
| Brent | 52 | 22 | 42.3% | 37.5% |
| Barnet | 56 | 25 | 44.6% | 49.4% |
| London, all 33 boroughs | 1,017 | 224 | 22.0% | 41.7% |
Sources: MHCLG Table PDR1, district planning authority prior approval applications, January to March 2026 — a single quarter, not a trend. Housing stock from VOA Council Tax Stock of Properties table CTSOP3.1 as at 31 March 2025, counts rounded to the nearest 10 at source. Both Open Government Licence v3.0, retrieved 2 September 2026.
Permitted development is not one right. It is a set of them, each with its own limits, and the first job on any project is working out which one you are actually relying on — because the drawings, the fee and the deadline all differ.
| What you want | Route | Council deadline | Statutory fee |
|---|---|---|---|
| Single-storey rear extension within the standard limits | Permitted development, no notification | — | £0 |
| Single-storey rear extension 4–6 m (attached) or 4–8 m (detached) | Larger householder prior approval | 42 days | £120 |
| Loft conversion within 40 or 50 m³ | Permitted development, no notification | — | £0 |
| Certainty that any of the above is lawful | Lawful Development Certificate | 8 weeks | £274 |
| Anything outside those limits, or on designated land | Householder planning application | 8 weeks | £548 |
The 42-day deadline on prior approval is the one worth understanding. If the council does not determine a valid submission inside it, and you notified correctly, you may build. That makes a complete, correct submission worth more here than anywhere else in the system — an invalid one does not start the clock at all.
They say that the borough is a bigger variable than the design. Across London, 224 of 1,017 larger householder extension decisions were refused in the first quarter of 2026 — 22.0%. But nobody applies in ‘London’.
In Enfield, 4 of 68 were refused. In Barnet, 25 of 56 — a rate seven and a half times higher on a similar number of decisions. Harrow decided more of these than any other borough at 121, and refused 24.0% of them.
One number needs a caveat rather than an explanation. Five boroughs — the City of London, Westminster, Kensington and Chelsea, Hammersmith and Fulham, and Kingston upon Thames — recorded no larger householder prior approvals at all in the quarter. For the first four that is consistent with conservation area designation and Article 4 directions having removed the right across most of their housing. Kingston is not obviously in that category, and the dataset does not say why. A recorded zero means no decisions were reported for that quarter; it is not evidence that the right does not exist there.
The larger householder extension right applies to houses. It does not apply to flats. That single fact explains most of the variation above, and it is measurable.
Of London's 3,837,410 homes, 41.7% are houses rather than flats or maisonettes — and that share ranges from 1.2% in the City of London and 8.7% in Westminster to 72.2% in Bexley and 73.8% in Havering.
| Borough | Homes | Share that are houses | What that means for you |
|---|---|---|---|
| Havering | — | 73.8% | Most addresses can use householder PD rights |
| Bexley | — | 72.2% | Most addresses can use householder PD rights |
| Redbridge | 108,080 | 64.1% | 38,090 two- and three-bed terraces |
| Barnet | 160,460 | 49.4% | Half the stock, but the highest refusal rate |
| Camden | — | 11.7% | Nearly nine in ten homes are flats |
| Westminster | 132,190 | 8.7% | PD extension rarely available |
Grouped, the pattern is unambiguous: the fifteen boroughs where at least half the homes are houses averaged 47.3 larger extension decisions in the quarter. The ten where fewer than a quarter are houses averaged 2.4. Two independent government datasets, agreeing.
If you live in a flat, none of this applies and the route is a full application — our planning drawings cover that. If you live in a house in an outer borough, prior approval is very often the faster and cheaper way in.
They answer different questions. Prior approval asks the council to accept a specific larger extension after consulting your neighbours. A Lawful Development Certificate asks the council to confirm that what you propose is lawful without permission at all.
The certificate is the right choice whenever the position is arguable, because it settles the question on a legal test rather than a planning judgement, and it is the document a buyer's solicitor will ask for in ten years' time. It costs £274 against £548 for a householder application, and Planning Inspectorate data shows 38.2% of the 1,510 lawful development certificate appeals decided in London were allowed — a materially better rate than the 22.4% for minor dwellings appeals.
Source: Planning Inspectorate appeals casework, decided appeals only; withdrawn, invalid and unrecorded outcomes are excluded from the denominator. Retrieved 1 September 2026. Open Government Licence v3.0.
| Package | Our fixed fee | Council fee on top |
|---|---|---|
| Essentials — survey and drawings for prior approval or an LDC | from £840 | £120 or £274 |
| Loft conversion package | from £1,225 | £274 for an LDC |
| Complete — planning plus building regulations | from £1,750 | £548 householder |
Building regulations approval is required either way. Permitted development removes the need for planning permission, never the need to build to the regulations, and our building regulations drawings cover that half.
That the proposal falls inside Class A of the General Permitted Development Order — which is a list of dimensional limits, not a matter of taste. A case officer is not deciding whether your extension is good. They are checking numbers against a schedule, and a drawing that does not put those numbers on the sheet gives them nothing to check. Every limit below has to be answerable from your plans and elevations without anyone reaching for a scale rule.
| Test | Limit | What the drawing must show |
|---|---|---|
| Curtilage cover | Buildings other than the original house may not exceed 50% of the curtilage | A site plan with both areas figured, outbuildings included |
| Forward of the principal elevation | Not permitted at all | Which wall is the principal elevation, and the highway it fronts |
| Overall height | No higher than the highest part of the existing roof | Both ridges dimensioned on the same elevation |
| Single-storey rear depth | 4m detached, 3m otherwise — or 8m and 6m under prior approval, and not on article 2(3) land | Depth measured from the original rear wall, not today’s |
| Single-storey rear height | 4m | Height to the top of the new roof, from ground level |
| Within 2m of a boundary | Eaves no higher than 3m | Boundary offset, and eaves height marked separately from ridge |
| More than one storey | 3m deep, and no closer than 7m to the rear boundary | The 7m dimension, which is the one most often left off |
| Side extension | Single storey, 4m high, no wider than half the original house | Original width and proposed width, both figured |
| Materials | Similar appearance to the existing house | A materials note on the elevations, conservatories excepted |
Source: Town and Country Planning (General Permitted Development) (England) Order 2015 (SI 2015/596), Schedule 2, Part 1, Class A, paragraphs A.1 and A.3. Retrieved 3 September 2026. Open Government Licence v3.0.
It does not mean the house as you bought it. Under the Order, original means the house as it stood on 1 July 1948, or as first built if that came later. Every depth and width limit above is measured from that house, not from the one in front of you.
This is the single most common reason a permitted development claim fails, and it fails late. A 1970s rear addition of two metres does not reset the clock — it spends two of your metres. Add three more and you are at five from the original wall, outside Class A, and building without permission. The previous owner’s conservatory counts against you in exactly the same way, and so does anything a former owner built without telling anyone.
So the first drawing on a permitted development job is often not the proposal at all. It is a reconstruction of what was there before, taken from historic mapping, the deeds, and what the fabric itself shows on a survey. Getting that wrong does not produce a refusal; it produces a Lawful Development Certificate refused on the facts, or worse, a certificate granted on a description that turns out to be untrue when someone complains.
A permitted development route for a single-storey rear extension longer than the standard limit — up to 6 metres on an attached house or 8 metres on a detached one. It is not automatic. You notify the council, neighbours are consulted, and if any of them objects the council decides whether the impact is acceptable.
Across the 33 boroughs, 1,017 larger householder extension decisions were made in January to March 2026 and 224 were refused — 22.0%. The spread between boroughs is far wider than that average: Enfield refused 4 of 68, while Barnet refused 25 of 56.
Usually. The council has 42 days from a valid submission, against eight weeks for a householder planning application. If it does not determine it in time and you have notified correctly, you may proceed. That deadline is why an incomplete submission is expensive here in a way it is not elsewhere.
Not for the larger householder extension, and often not for much else. Conservation areas are designated land, and an Article 4 direction can remove further rights on top. Five London boroughs recorded no larger householder prior approvals at all in the quarter, which is consistent with the right having been removed across most of their housing.
Yes. A prior approval submission needs a plan of the site, a drawing showing the proposed extension with its dimensions, and the addresses of the adjoining properties. A Lawful Development Certificate, which is the safer route where the position is arguable, needs a full drawing set.
Our Essentials package is a fixed £840 and covers the survey and the drawings for a prior approval or a Lawful Development Certificate. The statutory fee you pay the council is separate: £120 for larger householder prior approval and £274 for a Lawful Development Certificate.
Site plans are included in every drawing package we produce, on a licensed Ordnance Survey base with the ownership edging done properly.
Get a quote
Before you commit, it is worth understanding what it costs and seeing why homeowners choose us. You can search the site to find the right fit, or contact us to talk it through. When you are ready, get a quote today — most homeowners have a fee in minutes — or contact us about your project and an architectural technologist will be in touch.
Each area page carries the local planning authority, conservation-area position, postcode districts and typical housing stock for that address.
