Prior approval for a larger rear extension in Barnet, checked against the borough's constraints first
Barnet has the data for a clear answer and the constraint maps for a trap. Over the eight quarters to 2026 Q2 its council recorded 355 larger home extension notifications as prior approval not required, 31 granted and 211 refused. We check your address for conservation area and Article 4 limits first, then draw the set, for a fixed £595.
Fixed fee from £395 drawings + £200 survey (£595 total) · all prices
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Barnet's outcomes, counted
From MHCLG's quarterly planning statistics, across 2024 Q3 to 2026 Q2 Barnet recorded 355 larger home extension notifications where prior approval was not required, 31 where it was granted and 211 where it was refused.
The large "not required" group is a go-ahead. Among the 242 that needed a decision, 211 were refused, which is about 87% by our calculation. Those are this borough's counts only; we do not read anything into how they compare with another council, because registers are not kept alike.
Prior Approval Extension Barnet
from £595
£395 drawings + £200 survey (£595 total)
Every price is the full fixed fee you pay. No VAT is charged. Council application fees are paid to the council separately.
What you get
- A measured survey visit to the house and garden
- A constraints check of your address before drawing starts
- Existing and proposed ground floor plan and rear elevation
- Depth, maximum height and eaves height written out for the council
- The list of adjoining addresses the council must notify
- Submission as your agent, with replies to the council's questions
- Constraints first
We check conservation areas and Article 4 directions for your address.
- Survey the house
Measure the rear wall, the neighbours' extensions and the garden.
- Draw the notification
Plans, rear elevation, the written description and adjoining addresses.
- Council notifies neighbours
Neighbours get at least 21 days to comment on the effect on their homes.
- Decision by day 42
Not required, granted or refused; silence after 42 days lets work start.
The constraint maps are the first job
The Planning Data Platform lists 16 live conservation areas in Barnet. Houses inside them cannot use the 6 m or 8 m depths, so a deeper extension there needs a planning application.
The same register shows 48 Article 4 direction areas across all classes of development. We cannot tell from that number which of them touch extensions, so we read the direction for your address on the survey day rather than assuming. An Article 4 direction covering Class A would take the right away entirely.
The Planning Data Platform lists 16 live conservation areas in Barnet.
What a decision turns on
With 211 refusals recorded, it is worth drawing for the one person who will read the set closely: the neighbour whose boundary the extension follows. We state the depth, the maximum height and the eaves height in the written description, as the order asks, and show the height at the boundary on the elevation.
Our prior approval service page sets out the limits: 6 m for a house other than a detached one, 8 m for a detached house, no more than 4 m high, and a council fee of £249 paid to the council.
If the answer is no
If the constraints check rules the scheme out, the survey is not wasted. The same measurements feed a householder planning application for the same extension, and we tell you which route fits before anything is sent to the council.
Sources
Every figure on this page, where it comes from and a link to the original.
| Figure | Source | Link |
|---|---|---|
| 6 metres | GPDO 2015 Sch 2 Pt 1 Class A.1(g): larger single-storey rear extension, maximum depth beyond the rear wall for a house other than detached, subject to prior approval under A.4 (source wording: "6 metres") | www.legislation.gov.uk |
| 8 metres | GPDO 2015 Sch 2 Pt 1 Class A.1(g): larger single-storey rear extension, maximum depth beyond the rear wall for a detached house (source wording: "8 metres") | www.legislation.gov.uk |
| 4 metres | GPDO 2015 Sch 2 Pt 1 Class A.1(f)-(g): a single-storey rear extension may not exceed 4 metres in height (source wording: "exceed 4 metres in height") | www.legislation.gov.uk |
| 42 days | GPDO 2015 Sch 2 Pt 1 Class A.4(10)(c): work may start if the council has not notified a decision within 42 days of receiving the information (source wording: "the expiry of 42 days") | www.legislation.gov.uk |
| £249 | Statutory fee from 1 April 2026: prior approval for a householder larger rear extension (GPDO Part 1 Class A) | assets.publishing.service.gov.uk |
| 355 | Our analysis of MHCLG planning application statistics, table PS1 (district open data table) (released 24 Sep 2026, quarters to 2026 Q2) | www.gov.uk |
| 31 | Our analysis of MHCLG planning application statistics, table PS1 (district open data table) (released 24 Sep 2026, quarters to 2026 Q2) | www.gov.uk |
| 211 | Our analysis of MHCLG planning application statistics, table PS1 (district open data table) (released 24 Sep 2026, quarters to 2026 Q2) | www.gov.uk |
| 16 | Our analysis of the MHCLG Planning Data Platform conservation-area register (extracted 19 Oct 2026) | www.planning.data.gov.uk |
| 48 | Our analysis of the MHCLG Planning Data Platform article-4-direction-area register (extracted 19 Oct 2026) | www.planning.data.gov.uk |
Questions people ask
How many larger extension notifications did Barnet refuse?
Does my house in Barnet qualify?
Barnet has 48 Article 4 areas. Do they stop extensions?
How long does the council take?
What is the council's fee?
Photographs: David Howard (CC BY-SA 2.0).
