Change of Use Planning Permission in London: Use Classes, Permitted Development Changes, and Prior Approval

**What the Use Classes Order is**:

The Town and Country Planning (Use Classes) Order 1987 (as amended, most significantly in 2020) groups buildings into use classes based on their function and intensity of use. A building can be used for any purpose within the same use class without needing planning permission (a change of use within a use class is not 'development' for planning purposes). A change from one use class to another requires planning permission — or, in some cases, benefits from permitted development rights under the GPDO 2015 that allow the change without a full planning application.

**The current use classes relevant to London residential and mixed-use development (as of 2025)**:

*Class F.1 (Learning and Non-Residential Institutions)*: Includes: schools; libraries; art galleries; museums; non-residential training centres; creches; day nurseries.

*Class F.2 (Local Community Use)*: Includes: shops of up to 280m² in local areas where there is no other such use within 1,000 metres; local community halls; community facilities.

*Class C1 (Hotels)*: Hotels; boarding and guest houses; hostels. Use by more than 6 persons: C1. A property used as a large House in Multiple Occupation (more than 6 people sharing) that is not a C4 property is in a Sui Generis category.

*Class C2 (Residential Institutions)*: Residential care homes; hospitals; nursing homes; boarding schools; residential colleges.

• *Class C3 (Dwellinghouses)*:
• The standard residential use class for a house or flat occupied as a single household. C3 is subdivided:
• •C3(a): single household
• •C3(b): up to 6 people living together as a single household (sharing facilities but not an HMO in the HMO Act sense — e.g., a student house managed as a single let)
• •C3(c): up to 6 people living together who are not related but have been placed there under care or support arrangements

*Class C4 (Houses in Multiple Occupation)*: Small Houses in Multiple Occupation: between 3 and 6 people sharing facilities. Used as their only or main residence. A 'small HMO' under planning law — 3–6 occupants sharing a kitchen and/or bathroom. (Note: this is different from the HMO licensing threshold under the Housing Act 2004, which is triggered by 5 or more people in 2 or more households.)

• *Sui Generis (beyond use classes)*:
• Certain uses are not within any use class — they are 'sui generis' (a class of their own) and any change to or from them requires planning permission:
• •Large HMO (7 or more occupants): Sui Generis
• •Petrol stations; nightclubs; theatres; casinos; amusement arcades; laundrettes; taxi businesses; hot food takeaways; venues for live music; scrap yards

• *Class E (Commercial, Business and Service)*:
• The 2020 revision of the Use Classes Order created Class E by merging what had previously been separate Classes A1 (retail shops), A2 (financial and professional services), A3 (restaurants and cafes), B1 (offices; light industrial; research and development). This allows a very wide range of commercial uses within a single building without needing planning permission to change between them:
• •Retail (formerly A1): shops; supermarkets; hairdressers; funeral parlours
• •Financial/professional services (formerly A2): banks; estate agents; insurance brokers
• •Cafes and restaurants (formerly A3): cafes; restaurants (NOT hot food takeaways or nightclubs)
• •Offices (formerly B1a): offices; call centres; administrative functions
• •Research and development (formerly B1b)
• •Light industrial (formerly B1c): light manufacturing; assembly
• •Health centres; creches; gyms; indoor sports facilities

*Class B2 (General Industrial)*: General manufacturing and industrial processes.

*Class B8 (Storage and Distribution)*: Warehousing; storage; distribution.

*Class C (Change of Use rights between C3 and C4)*: A C3 dwelling can change to a C4 small HMO (3–6 occupants) WITHOUT planning permission — this is permitted development under the GPDO 2015 Part 3, Class L. HOWEVER, many London Boroughs have made Article 4 Directions that withdraw this permitted development right — requiring planning permission for C3 to C4 changes in designated areas. Similarly, a C4 HMO can change back to a C3 dwelling without planning permission (Class L in reverse).

**Permitted development change of use rights under Part 3 of the GPDO 2015**:

Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015 sets out the permitted development rights for changes of use. The most relevant Part 3 rights for London residential and mixed-use property:

*Class MA — Class E to C3 (commercial to residential) Prior Approval*:

One of the most significant and frequently used change of use routes in London. Class MA allows the conversion of a building in Class E (Commercial, Business and Service — formerly offices, retail, cafes, light industrial) to Class C3 (residential) through a Prior Approval application, not a full planning permission.

• *Class MA eligibility criteria (as of 2025)*:
• •The building must have been in Class E use (or a predecessor A1/A2/A3/B1 use) for a continuous period of at least 2 years immediately before the Prior Approval application
• •The building must have been vacant for at least 3 consecutive months immediately before the Prior Approval application
• •The building must not exceed a floorspace of 1,500m² (above this threshold, Class MA does not apply)
• •The change of use must result in one or more C3 dwellings (the whole building or a portion of it is converted)
• •The prior approval application must include a flood risk statement (in Flood Zones 2 and 3); a noise assessment (if in proximity to commercial noise sources); a light assessment; and a transport statement where relevant

*London-specific restriction on Class MA — Article 4 Directions in Central London and some London Boroughs*: Many London Boroughs, particularly in Inner London, have made Article 4 Directions that withdraw Class MA permitted development rights within defined areas — particularly in designated employment areas (industrial and commercial zones) and 'Protected Employment Areas' designated in the Local Plan. The rationale is to protect commercial floorspace and employment uses from conversion to residential. Before assuming Class MA applies to a specific London property, the Article 4 Direction status must be checked.

*Class L — C4 to C3 and C3 to C4 (HMO)*: Permits change of use between C3 (single dwelling) and C4 (small HMO, 3–6 occupants) without planning permission. This is permitted development in both directions. However, as noted above, many London Boroughs have made Article 4 Directions withdrawing Class L rights in areas with high concentrations of HMOs — particularly in areas covered by Houses in Multiple Occupation planning policies that restrict the proportion of HMOs in a street or area.

*Class N — Student Accommodation to C3*: Permits change of use from certain sui generis student accommodation to C3 (residential) without planning permission. Relevant for developers seeking to convert purpose-built student accommodation to mainstream residential.

*Class P — Storage (B8) to C3*: Permits change of use from B8 (storage and distribution) to C3 (dwellings) subject to Prior Approval — relevant for warehouse-to-residential conversions in London.

**London Borough Article 4 Directions affecting change of use permitted development rights**:

The following types of Article 4 Directions affecting change of use rights are common in London:

*1. C3 to C4 Article 4 Directions (HMO restriction)*: Borough-wide or area-specific Article 4 Directions withdrawing Class L (C3 to C4) PD rights. Common in Outer London Boroughs (Harrow; Waltham Forest; Redbridge; Ealing; Brent; Sutton; Croydon) where HMO concentrations are high. Check the Borough's planning portal for the specific Article 4 Direction boundary map — some Boroughs apply the restriction across the entire Borough; others only in specific wards.

*2. Class MA Article 4 Directions (E to C3 restriction)*: Inner London Boroughs (Camden; Islington; Hackney; Tower Hamlets; Southwark; Lewisham) have made Article 4 Directions withdrawing Class MA rights in designated employment areas and strategic industrial locations. Also: the City of London has an Article 4 Direction protecting office floorspace in the Square Mile from Class MA residential conversion.

*3. Conservation area Article 4 Directions affecting commercial use*: In some London conservation areas, Article 4 Directions restrict changes of use that would affect ground floor commercial frontage — particularly in town centre conservation areas where the LPA wishes to protect retail and commercial uses at street level.

**What Prior Approval means for change of use**:

A Prior Approval application is a reduced-form planning application that is used for certain permitted development changes of use. It is not a full planning application — the LPA's ability to object is limited to the specific matters prescribed in the relevant Part 3 class:

• For Class MA (E to C3 residential conversion), the Prior Approval matters are:
• •Transport impacts of the development
• •Contamination risks
• •Flooding risks (relevant in Flood Zones 2 and 3)
• •Noise impacts from surrounding commercial uses on the proposed residential use
• •The impact of the loss of commercial floorspace in the local area
• •The adequacy of natural light for proposed residential units
• •The provision of adequate amenity space

*The LPA CANNOT refuse a Class MA Prior Approval application on grounds of residential design quality, appearance, impact on the street scene, or overshadowing of neighbouring residential properties* — the assessment is limited to the prescribed matters above. This is a significant advantage of the Prior Approval route over a full planning application, where the LPA can refuse on any material planning consideration.

**Prior Approval application process for Class MA**:

1. *Submit the Prior Approval application*: via the Planning Portal or the LPA's own planning portal. Required documents: site location plan; floor plans and elevations showing the proposed residential layout; transport statement (if required by the LPA's pre-application requirements); flood risk assessment (if in Flood Zone 2 or 3); noise assessment (if in proximity to commercial noise sources); contamination risk assessment (if the building is on previously contaminated land); daylight assessment (demonstrating adequate natural light for the proposed dwellings)

2. *The 56-day Prior Approval determination period*: the LPA has 56 days from validation to determine the Prior Approval application. If the LPA fails to respond within 56 days, the Prior Approval is deemed to have been granted automatically — development can proceed

• 3. *Possible outcomes*:
• •Prior Approval granted: development can proceed as specified in the Prior Approval. The LPA may attach conditions relating to the prescribed matters (e.g., noise mitigation measures; contamination remediation; access and transport measures)
• •Prior Approval refused: grounds for refusal are limited to the prescribed matters — the applicant can appeal a Prior Approval refusal on the same grounds

• **Application fee for Prior Approval Class MA (2025)**:
• •£100 per residential unit proposed — the fee is capped at £15,000 in total for very large schemes. For a 10-unit conversion: £1,000. For a 50-unit conversion: £5,000

**When Prior Approval is NOT sufficient — when a full planning application is needed for change of use in London**:

• •Where the Article 4 Direction has removed the relevant PD right (see above)
• •Where external alterations to the building are proposed as part of the change of use (e.g., new windows; new rear extension to the commercial unit) — Prior Approval covers the change of use only; external alterations affecting the building's appearance typically require planning permission
• •Where the building exceeds 1,500m² (Class MA cap)
• •Where the building has not been in E-class use for 2 years, or has not been vacant for 3 consecutive months
• •Where the LPA's pre-application check confirms the Article 4 Direction applies to the site
• •Where additional residential units are to be created by extension (not just by conversion of the existing building) — the extension element requires planning permission

**Costs overview for a change of use project in London (2025)**:

| Type | Prior Approval fee | Full planning application fee | |---|---|---| | Class MA (E to C3): per unit | £100/unit | N/A | | C3 to C4 HMO (where PA required): per unit | N/A | £258 (householder) | | C4 HMO (6 occupants) to larger HMO (7+): Sui Generis | N/A | £578 (minor works) | | Full planning permission: any change of use | N/A | £578 (minor works) or higher for larger schemes | | Planning consultant for Prior Approval application (London) | £1,500–£4,000 | £3,000–£8,000+ |

*Pre-application advice strongly recommended for any London change of use project — see `pre-application-planning-guide` for guidance on using the pre-app service.*