Certificate of Lawful Development Secured from Lambeth for Exisitng Works
Lambeth grants lawful development certificate for rear extension built over four years ago.
COL APPROVALSLAMBETHLONDON
Andrew Ransome
7/24/20262 min read
In 2024, the London Borough of Lambeth issued a Certificate of Lawful Development confirming that a single-storey rear extension — replacing a conservatory at a ground-floor flat — constituted permitted development under Part 1 of the General Permitted Development Order 2015.
The certificate provides the homeowner with formal legal certainty that no planning permission was required and the extension is immune from enforcement action.
Proving an Existing Extension is Lawful: A Successful Outcome in Lambeth
The application related to a ground-floor flat within a two-storey terraced property in the London Borough of Lambeth. The property was already lawfully established as two self-contained flats.
Our client sought a Certificate of Lawfulness (Existing) for a single-storey rear extension that had replaced a former conservatory. The extension had been completed several years previously and remained in continuous use.
A Certificate of Lawfulness is determined under Section 191 of the Town and Country Planning Act 1990. The key question is not whether development is acceptable in planning terms, but whether it has become lawful through the passage of time.
As the application was submitted before 25 April 2024, the relevant immunity period for operational development remained four years.
Consequently, the applicant needed to demonstrate, on the balance of probability, that the extension had been substantially completed and continuously in place for at least four years before the application date.
The Council reviewed the submitted evidence against the legal test and concluded that it was sufficiently clear, precise and unambiguous.
Importantly, the Council held no contradictory evidence that would challenge the applicant's claim that the extension had been in place continuously for the required period.
Lambeth Council issued a Certificate of Lawfulness (Existing), formally confirming that the single-storey rear extension is lawful in planning terms.
Planning Application Advice
If you have carried out extensions or alterations without planning permission and want to establish your legal position, a Certificate of Lawful Development provides the certainty you need. Contact me to discuss your situation.
Andrew Ransome MRTPI - Email: andrew@andrewransome.co.uk
About me
Andrew Ransome is a Planning Director and a Chartered Member of the Royal Town Planning Institute (RTPI), with more than two decades of experience in town planning.
He specialises in delivering strategic planning solutions for complex developments across both rural and urban environments, helping clients navigate planning challenges and unlock development opportunities. Connect with Andrew on Linkedin.
Certificate of Lawfulness Successes
Permitted Development Information
Get in touch for planning advice: Email: andrew@andrewransome.co.uk
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