Class L Permitted Development Rights

Class L of Schedule 2, Part 3 to the GPDO 2015 grants permitted development rights for the change of use between a C3 dwelling house (a standard family home) and a C4 small HMO (a house in multiple occupation occupied by 3 to 6 unrelated people). This right works in both directions — C3 to C4, and C4 back to C3 — without any planning application.

This right was introduced to reflect the practical reality that many houses are let to groups of students or young professionals without any formal change of use having been applied for. However, it came with a significant caveat: LPAs can remove it using an Article 4 Direction.

What an A4D Removes for HMOs

Where an LPA has made and confirmed an A4D removing Class L rights in an area:

• Converting a C3 dwelling to a C4 HMO (3–6 unrelated tenants) requires a full planning application.
• The LPA will assess the application against its policies on HMO concentrations, parking, amenity, and the character of the area.
• The LPA can — and often will — refuse permission if the proportion of HMOs in the street or ward exceeds a threshold set in the Local Plan.

Many LPAs set a threshold of around 10–20% of properties in a defined area as HMOs. If this threshold is exceeded, a planning application is likely to be refused on policy grounds.

Areas with HMO Article 4 Directions

HMO Article 4 Directions are widespread in university cities, London, and areas of high private rented sector density. The following have borough-wide or near-borough-wide Class L A4Ds:

• London boroughs: Camden, Islington, Southwark, Newham, Hackney, Tower Hamlets, Waltham Forest, and others.
• University cities: Oxford, Cambridge, Bristol, Leeds, Sheffield, Nottingham, Leicester, Portsmouth.
• Other areas: Brighton & Hove, Reading, Bournemouth, Coventry.

This is not an exhaustive list — check your LPA’s website. New A4Ds are made regularly. The position as of mid-2025 is that the majority of urban LPAs in England have introduced at least a partial HMO A4D.

Already Converted Without Permission?

If you have already converted a C3 dwelling to a C4 HMO in an area where an A4D removes Class L rights — and you did not obtain planning permission — you have a potential enforcement issue. Your options are:

• Retrospective planning application: Apply for planning permission for the existing use. If granted, the breach is regularised. If refused, you will need to revert the property to C3 use.
• Certificate of Lawfulness (LDC — existing use): If the C4 use has been continuous for 4 years without enforcement action being taken, you may be able to apply for an LDC confirming the use is now lawful. Note: this is not a permanent “get out of jail free” card — it confirms the use is immune from enforcement, not that it is consented.

Before taking either route, take specialist planning advice. If an enforcement notice has already been issued, time limits for appeal apply and you should act quickly.

Small HMOs vs Large HMOs

The C3/C4 boundary is important:

• C4 (small HMO): 3–6 unrelated occupiers sharing facilities. Class L PD right applies (unless removed by A4D). Mandatory HMO licence required for 5+ occupiers sharing a single dwelling.
• Sui Generis (large HMO): 7 or more unrelated occupiers. No PD right has ever existed for this — planning permission is always required for conversion from C3. Mandatory HMO licence required. Some LPAs require additional licensing for smaller HMOs too.

HMO Licensing vs Planning Permission

HMO licensing and planning permission are entirely separate regimes administered by different parts of the council:

• HMO licensing is a housing management matter. It governs standards, safety, and landlord fitness. It is required by law regardless of whether planning permission is needed and does not regularise a planning breach.
• Planning permission governs the use of land and buildings. If an A4D removes Class L rights, you need planning consent for the change of use before letting to multiple unrelated tenants — holding an HMO licence does not fix a planning breach.