Southwark's certificate does three different jobs. We work out which one you need, check the Article 4 map for your street, and draw it.
Southwark's page on whether you need planning permission lists what a certificate is for. First, to confirm that planned works do not need planning permission, for example because they are permitted development. Second, to check whether the existing use of a building is lawful for planning purposes. Third, to check whether completed works are immune from planning enforcement action. The council stresses it provides proof that your building is legal and is not the same as planning permission.
The first is the common one for a homeowner about to build a rear extension or loft dormer. The third is the one that sells houses: a conservatory or dormer built years ago without paperwork, which a buyer's solicitor now wants evidence for. Southwark also reminds you that it helps to know a property's history, which you can check on the Planning Register, and that if you made changes that needed permission you can still apply for it now, although it will assess the application in the usual way.
For the first, the limits are the statutory ones. Southwark's Householder SPD says permitted development for dormers and rear extensions does not apply to flats and maisonettes or to homes in a conservation area or listed. Class B gives 40 cubic metres on a terrace and 50 on other houses; Class A gives 3 metres at the rear, or 4 on a detached house. A certificate shows the drawings meet them.
The council's own page names three purposes for a lawful development certificate.
| Purpose | Typical Southwark case | Application type |
|---|---|---|
| Planned works need no permission | Rear dormer or single-storey extension on a house | Proposed development |
| Existing use is lawful | A long-standing use or conversion with evidence | Existing use |
| Completed works immune from enforcement | An old extension or dormer built without consent | Existing development |
Southwark Council, Check if you need planning permission, read 25 October 2026.
The fee includes our measured visit. The bracketed figure applies if you already have measured drawings.
Southwark's Article 4 page lists directions for the Sunray Estate, houses in multiple occupation, railway arches, Class E to residential, demolition, public houses, the Central Activities Zone, the Old Southern Railway Stables and the Forge, 41 Linden Grove SE15, communications equipment on Croxted Road and Norwood Road, and the Great North Wood. It adds that Article 4 directions do not apply retrospectively and do not apply to past development.
That non-retrospective rule helps an existing-development certificate: work completed before a direction took effect is judged against the rights that existed then. For proposed work, the Sunray Estate direction in north Dulwich is the one that bites householders, since you must apply for planning permission there for development covering Sunray Avenue, Sunray Gardens, Casino Avenue, Nairne Grove, Red Post Hill and part of Herne Hill. A certificate for a rear dormer on Casino Avenue will be refused.
Southwark decided 435 householder applications in the year to June 2026 with prior approvals set aside and 424 inside 8 weeks. The council fee for a proposed-use certificate is half the planning fee for the same development.
Every figure is linked to the page or document we read.
Southwark says a lawful development certificate can confirm planned works need no permission, check an existing use is lawful, or check that completed works are immune from enforcement, which makes 3 distinct uses.
Source: Southwark Council, Check if you need planning permissionSouthwark's Article 4 page lists 11 direction areas or topics and says directions do not apply retrospectively to past development.
Source: Southwark Council, Article 4 directionsThe Sunray Estate conservation area in north Dulwich has an Article 4 direction, so you must apply for planning permission to develop there.
Source: Southwark Council, Article 4 directions: Sunray EstateSouthwark's Householder SPD of July 2025 says a rear dormer under permitted development can be up to 40 cubic metres on a terrace or 50 cubic metres on a semi or detached house, but not on flats or in conservation areas.
Source: Southwark Council, Householder SPD, July 2025, section 3.6.1The council must decide a lawful development certificate within 8 weeks, and the fee for a proposed-use certificate is 50% of the planning fee.
Source: GOV.UK, Fees for planning applicationsSouthwark decided 435 householder applications between July 2025 and June 2026, prior approvals excluded, and 424 of them were decided within 8 weeks.
Source: MHCLG, Planning application statistics PS2, July 2025 to June 2026Under Class A, a single-storey rear extension may reach 3 metres on an attached house or 4 metres on a detached house without an application.
Source: legislation.gov.uk, GPDO 2015, Schedule 2, Part 1, Class ATell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Southwark says to confirm planned works need no planning permission, to check whether the existing use of a building is lawful, or to check whether completed works are immune from enforcement action. It is proof, not planning permission.
No. The Householder SPD says permitted development for dormers does not apply to homes in a conservation area, so planning permission is needed. In the Sunray Estate the Article 4 direction also requires an application.
Southwark's page says Article 4 directions do not apply retrospectively and do not apply to past development. An existing-development certificate depends on the evidence that the work was completed and how long ago.
The statutory period is 8 weeks from receipt of a valid application. Southwark decided 424 of 435 householder applications within 8 weeks in the year to June 2026, which describes the borough, not your case.
£715 inc survey (£515 if you supply measured drawings). That covers the measured survey, the drawings and the application. Southwark's own fee is separate and goes to the council.
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