Lambeth tells homeowners to get a certificate before relying on permitted development. We draw the proposal, or assemble the evidence for work already built, and apply for you.
It depends on the date. Lambeth's Local Information Requirements 2024 explain, for a certificate of existing lawful development, that operational development such as a building extension is lawful if it was substantially completed four or more years before the application and before 25 April 2024. On or after that date the period to acquire lawfulness is extended from 4 to 10 years.
Changes of use follow a similar split. A residential use is lawful after four years of continuous use without significant interruption, or 10 years where the change of use began on or after 25 April 2024; other uses need 10 years. The onus is firmly on the applicant, in the council's words, to provide sufficient evidence to show lawfulness on the balance of probability, otherwise the application may be refused. So the evidence matters more than the drawings.
For proposed work the picture is simpler. Lambeth's page on whether you need permission says houses may have permitted development rights, and recommends applying for a certificate of lawfulness before carrying out works, which gives a legal document confirming the works would comply with the legislation and, in its words, can give peace of mind. The council has been building an online service for these certificates, so we prepare the plans in the form it expects.
The 2024 Local List sets out when work becomes lawful through the passage of time.
| Situation | Period to become lawful |
|---|---|
| Building work substantially completed before 25 April 2024 | 4 years |
| Building work substantially completed on or after 25 April 2024 | 10 years |
| Change to residential use before 25 April 2024 | 4 years of continuous use |
| Change to residential use on or after 25 April 2024 | 10 years of continuous use |
| Any other change of use | 10 years |
Lambeth Council, Local Information Requirements 2024, item 31.
The fee includes our measured visit. The bracketed figure applies if you already have measured drawings.
Lambeth's Article 4 page lists nine conservation areas where all or part of the area has directions removing rights for external building alterations: Albert Square, Hyde Farm, Lansdowne Gardens, Leigham Court Estate, Park Hall Road, St Marks, Stockwell Park, Streatham Lodge and Vauxhall. It also lists directions withdrawing Class MA in 2022 and the Class C3 to C4 right for small HMOs in 2024. A certificate cannot confirm a right that a direction has taken away.
For example, a house in Albert Square cannot be certified for a rear extension the street's direction forbids, while a similar house outside the nine can. We read the direction for your address first.
Lambeth says a householder project should get a response in 8 weeks. It decided 354 householder applications in the year to June 2026 with prior approvals set aside and 333 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.
Lambeth's Local Information Requirements 2024 say building work substantially completed 4 or more years before the application and before 25 April 2024 is lawful, and that on or after that date the period is extended from 4 to 10 years.
Source: Lambeth Council, Local Information Requirements 2024, item 31On 25 October 2026 Lambeth's page recommended applying for a certificate of lawfulness before carrying out works that may have permitted development rights.
Source: Lambeth Council, Find out if you need planning permissionLambeth lists 9 conservation areas with Article 4 directions on external alterations, plus 2022 and 2024 directions on Class MA and small HMOs.
Source: Lambeth Council, Article 4 DirectionsLambeth says a householder project on an existing home should get a response in 8 weeks.
Source: Lambeth Council, Apply for householder planning permissionThe 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 applicationsLambeth decided 354 householder applications between July 2025 and June 2026, prior approvals excluded, and 333 of them were decided within 8 weeks.
Source: MHCLG, Planning application statistics PS2, July 2025 to June 2026Class B permits a roof extension of up to 40 cubic metres on a terraced house and 50 cubic metres in any other case.
Source: legislation.gov.uk, GPDO 2015, Schedule 2, Part 1, Class BTell 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.
Lambeth recommends it. Its guidance says that if you think the development has permitted development rights, you should apply for a certificate of lawfulness before carrying out works, because it is a legal document confirming the works would comply with the legislation.
Work substantially completed four or more years before the application, and before 25 April 2024, can be certified as lawful through time. Work completed on or after that date needs 10 years. The applicant must prove it on the balance of probability.
Lambeth's Local List says the applicant must submit sufficient evidence to demonstrate lawfulness on the balance of probability, with the onus firmly on you. The council says the evidence should demonstrate continuity, so dated records matter.
Albert Square, Hyde Farm, Lansdowne Gardens, Leigham Court Estate, Park Hall Road, St Marks, Stockwell Park, Streatham Lodge and Vauxhall, in all or part. A certificate cannot cover works the direction takes away.
£715 inc survey (£515 if you supply measured drawings). That covers the measured survey, the drawings and the application. Lambeth's own fee is separate and goes to the council.
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