London Planning Enforcement for Unauthorised Conversions

Housing and Building Standards England 3 Minutes Read ยท published February 02, 2026 Flag of England

In London, England, unauthorised conversions and creation of accessory dwelling units (ADUs) can trigger planning enforcement by local planning authorities. This guide explains how enforcement works, which powers councils use, how to report suspected breaches and the practical steps owners and neighbours can take to resolve issues in London, England. It is aimed at residents, developers and landlords seeking clear action steps, likely outcomes and official contacts for raising complaints with the relevant local planning authority.

Penalties & Enforcement

Local planning authorities use statutory powers under the Town and Country Planning Act 1990 to address breaches of planning control; these powers include enforcement notices, stop notices, breach of condition notices and injunctions. The controlling statutory provision for enforcement notices is set out in legislation and the procedure and discretionary remedies are described in government guidance [1][2]. For reporting and local action you must contact the local council responsible for the area where the property is located [3].

  • Enforcement notice - requires specified steps or removal of unauthorised development.
  • Stop notice - immediate halt to specified activities where harm is urgent.
  • Breach of condition notice - enforces compliance with planning conditions.
  • Injunctions or court orders - used for persistent or serious breaches.
  • Prosecution for non-compliance with notices - see statutory text for offence provisions.
Local councils decide enforcement action based on planning harm, proportionality and public interest.

Fine amounts and monetary penalties are not specified on the cited government guidance and the statutory text referenced below; specific sums or sentencing guidance are set by the courts or separate statutory penalty provisions and therefore are not specified on the cited page. Escalation for first, repeat or continuing offences is a matter of procedure and judicial sentencing and is also not specified on the cited page. Non-monetary sanctions commonly used include notices requiring remedial works, stop notices, injunctions and court orders. Inspectors and planning officers may enter premises as set out in statute and guidance when authorised.

Applications & Forms

There is no single national enforcement application form; reports and complaints are handled by the local planning authority for the area where the breach occurs. Councils commonly publish online complaint/report forms or email addresses to submit evidence and photos. Appeals against enforcement notices are made to the Planning Inspectorate or the courts as provided by statute and guidance; consult the local authority or the Planning Inspectorate for the specific appeal form and deadline.

How-To

  1. Collect evidence: dates, photographs, addresses and any planning permissions or conditions you have.
  2. Find and contact the local planning authority for the property and submit an enforcement complaint with your evidence. [3]
  3. Keep a record of the complaint reference, correspondence and any officer site visits.
  4. If the council serves an enforcement notice, check the notice carefully for required remedial steps and the appeal instructions.
  5. If you receive an enforcement notice and disagree, consider a timely appeal to the Planning Inspectorate or seek legal advice on grounds and remedies.
Act quickly to gather clear dated evidence before alterations are completed.

FAQ

Can I report an unauthorised conversion in my street?
Yes. Report the suspected breach to the local planning authority where the property is located and provide photos, dates and an address. The council will assess whether it is a breach of planning control.
Will the council always remove an unauthorised ADU?
Not always. The council evaluates planning harm and may negotiate remedies, require retrospective permission, or take formal enforcement action depending on the circumstances.
How long do I have to appeal an enforcement notice?
The precise appeal deadline and procedure are set out on the enforcement notice and in statutory guidance; check the notice and contact the Planning Inspectorate or council promptly for the deadline.

Key Takeaways

  • Enforcement is managed by the local planning authority using statutory powers under the Town and Country Planning Act 1990.
  • Report breaches to the local council with clear dated evidence; appeals follow statutory routes through the Planning Inspectorate or courts.

Help and Support / Resources

  1. [1] Town and Country Planning Act 1990, Section 172
  2. [2] GOV.UK: Planning enforcement guidance
  3. [3] GOV.UK: Find your local council

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