Change of Use Planning UK — Use Classes, HMOs, and Short-Term Lets

Use Classes Relevant to Residential Landlords — C3, C4, and Sui Generis

The Town and Country Planning (Use Classes) Order 1987 (as amended) divides land uses into classes. Changes within the same class do not constitute development and do not require planning permission. Changes between classes (or into sui generis uses) may require planning permission. The residential classes most relevant to landlords: (a) Use Class C3 — dwellinghouse: a property used as a single dwelling house by one person, a family, or a small group of people living together as a single household (up to 6 people who are not all family members); the C3 class has three sub-categories: C3(a) — single person or family; C3(b) — up to 6 residents living together as a single household (not a family), for example supported housing; C3(c) — other small groups of people living together (up to 6) not meeting the HMO definition; (b) Use Class C4 — Houses in Multiple Occupation (small HMO): a dwelling house occupied by 3 to 6 unrelated persons as their only or main residence, sharing basic amenities (kitchen, bathroom, or toilet); the change from C3 to C4 is permitted development (no planning permission required) UNLESS the local planning authority (LPA) has made an Article 4 Direction removing this permitted development right; where an Article 4 Direction applies, the landlord must obtain planning permission before converting a C3 property to a C4 small HMO; (c) Sui generis — large HMO: an HMO occupied by 7 or more unrelated persons; large HMOs are not within any use class (they are 'sui generis') and conversion from C3 or C4 to sui generis ALWAYS requires planning permission — there is no permitted development right; (d) Short-term lets and holiday accommodation: use of a property primarily as short-term holiday accommodation (via Airbnb or similar platforms) involves a change from C3 to a mixed or holiday use that may be sui generis or Class C1 (hotels and bed and breakfast) depending on the character of the use; in England, the government introduced a new Use Class C5 (short-term let) through the Town and Country Planning (Use Classes) (Amendment) (England) Order 2024, effective from May 2024 — from that date, the material change of use from C3 to C5 (principal home used for more than 90 nights a year as a short-term let) requires planning permission; properties in London were already restricted under the Deregulation Act 2015 (90-night rule without LPA consent).

• C3 to C4 (small HMO, 3-6 people): permitted development — no planning permission required unless an Article 4 Direction has removed this right in the relevant LPA area; check the LPA's planning policy before converting
• C4 to C3 (HMO back to dwellinghouse): always requires planning permission — there is no permitted development right for the change from C4 to C3; this was confirmed by the Town and Country Planning (Use Classes) (Amendment) (England) Order 2010
• C3 or C4 to sui generis (7+ HMO): always requires planning permission — large HMOs are outside the permitted development regime and there is no automatic permission for conversion
• New Use Class C5 (short-term let) from May 2024: using a property for more than 90 nights a year as a short-term let (where it is not the owner's principal home) constitutes a change from C3 to C5 requiring planning permission; the rule applies across England
• Article 4 Directions: local planning authorities can make an Article 4 Direction removing the C3 to C4 permitted development right for their area (or part of their area); landlords must check the LPA's Article 4 Direction map before converting to a small HMO — planning permission is required from that point

Article 4 Directions — Removing HMO Permitted Development Rights

An Article 4 Direction is made by a local planning authority under Article 4 of the Town and Country Planning (General Permitted Development) (England) Order 2015 (GPDO 2015). It removes specified permitted development rights within a defined area, requiring planning permission for developments that would otherwise not need it. Article 4 Directions are widely used to control the proliferation of HMOs in areas with high student or rental demand: (a) Who makes Article 4 Directions for HMOs: local planning authorities with significant HMO concentrations — university cities and towns such as Oxford, Cambridge, Leeds, Southampton, Birmingham, and many others; the LPA makes the Direction following a statutory consultation procedure; once confirmed, the Direction has effect in the designated area; (b) Effect on landlords: in an Article 4 Direction area, a landlord who converts a C3 property to a C4 HMO without obtaining planning permission is in breach of planning control; the LPA can serve an enforcement notice requiring the use to revert to C3; where the LPA refuses planning permission for C4 use in an Article 4 area, it must pay compensation to the landlord if the refusal was prompted by the Article 4 Direction (rather than a substantive planning objection); (c) How to find out if an Article 4 Direction applies: consult the LPA's planning portal, the Interactive Article 4 Direction map on the Planning Portal website, or contact the LPA's planning department directly; always confirm before committing to an HMO conversion in a major town or city; (d) Planning application for C3 to C4 in an Article 4 area: a full planning application is required; the LPA assesses the application against its local planning policy (including any HMO policy in the local plan); refusal is common where the LPA has a policy limiting HMO concentrations (e.g. no more than 10-20% of properties in a defined area to be in HMO use); (e) Purpose-built student accommodation (PBSA): large-scale purpose-built student blocks are typically sui generis and require full planning permission regardless of Article 4 Directions.

• Check for Article 4 Directions before any HMO conversion: widely in force in university cities; failure to check and convert without permission is a planning breach; enforcement notices and orders to revert to C3 can be issued
• Article 4 compensation: where an LPA refuses planning permission for C4 use solely because of the Article 4 Direction (not substantive objection), it must pay compensation for the loss of the permitted development right; this is rare but can be significant for large conversions
• LPA HMO concentration policy: in Article 4 areas, LPAs typically have policies limiting HMO concentrations in defined areas to 10-20% of properties; planning permission for new HMOs is frequently refused in areas that have already met the threshold
• Article 4 Direction map: check the Planning Portal's Interactive Article 4 Direction map or contact the LPA planning department before proceeding with any HMO conversion in a town or city area
• Large HMOs (7+ people) always need planning permission: Article 4 Directions are relevant for C3-to-C4 conversions; large HMOs (sui generis) always require planning permission regardless of Article 4

Prior Approval for Commercial to Residential Conversion — Class MA

The General Permitted Development Order (GPDO) 2015 as amended includes a prior approval route for converting commercial premises to residential dwellings. The key current route is Class MA (formerly Class O for offices, and Class PA for light industrial): (a) Class MA — commercial, business and service to residential: Part 3, Class MA of the GPDO 2015 allows the conversion of buildings in Use Class E (commercial, business and service — which includes offices, shops, gyms, and light industrial premises) to residential use (Class C3) without a full planning application, subject to prior approval; (b) What triggers prior approval: unlike a full planning application, prior approval is a lighter-touch process in which the LPA only considers specified matters: transport and highways impacts; contamination risks; flood risk; noise impacts from existing commercial uses; the impact on natural light in habitable rooms; and the impact on the provision of services in the area; the LPA cannot refuse prior approval on general planning policy grounds (such as the loss of commercial floorspace) — only the specified matters are in play; (c) Size limits: a single prior approval application under Class MA can convert up to 1,500 sq m of commercial floorspace to residential use in a single application; above 1,500 sq m, a full planning application is required; (d) The 56-day default: if the LPA does not determine a prior approval application within 56 days of valid submission, the prior approval is deemed to be granted; a developer who proceeds after the 56-day period can do so as of right; (e) Class Q — agricultural to residential (barn conversions): a separate prior approval route (Part 3, Class Q of the GPDO 2015) allows the conversion of agricultural buildings to residential dwellings; up to 5 dwellings from a single agricultural unit with a maximum of 465 sq m of total residential floorspace; the LPA assesses transport, noise, contamination, flood risk, and whether the building is capable of functioning as a dwellinghouse; the building must have been in agricultural use for at least 10 years before the date of the prior approval application.

• Class MA (GPDO 2015 Part 3): permits conversion of Use Class E buildings (offices, shops, light industrial) to residential C3 use without full planning permission; prior approval only covers specified matters (transport; contamination; flood risk; noise; natural light; services)
• 1,500 sq m limit: a single prior approval application covers up to 1,500 sq m of commercial floorspace; larger conversions require full planning permission
• 56-day default approval: if the LPA fails to determine the prior approval application within 56 days of valid submission, the prior approval is deemed granted — a powerful default that incentivises LPA decision-making
• Class Q (barn conversions): conversion of agricultural buildings to up to 5 dwellings per agricultural unit (maximum 465 sq m total floorspace) via prior approval; the building must have been in agricultural use for at least 10 years; the LPA only considers the specified matters, not general planning policy
• Loss of commercial floorspace not a ground for refusal: under Class MA and Class Q, the LPA cannot refuse prior approval on grounds of the loss of commercial or agricultural use — only the specified technical matters are within scope

Short-Term Lets, AirBnB, and the New Use Class C5

Short-term letting via platforms such as Airbnb, Vrbo, and Booking.com has created a significant planning challenge for local planning authorities in tourist areas and major cities. The planning position has evolved significantly with the introduction of Use Class C5: (a) The pre-May 2024 position: before the introduction of Use Class C5, a residential property used as short-term holiday accommodation would typically constitute a change of use from C3 to a sui generis or mixed use; whether planning permission was required depended on whether the change was a 'material change of use' (TCPA 1990 s.55) — which in turn depended on the frequency, nature, and extent of the letting; HMRC's guidance noted that using a property primarily as a short-term let (rather than occasionally) involved a material change of use; however, enforcement was inconsistent; (b) Use Class C5 from May 2024 (England): the Town and Country Planning (Use Classes) (Amendment) (England) Order 2024 created Use Class C5 (short-term let); the change from C3 to C5 is a change of use requiring planning permission; a property in C5 use is one used primarily as a short-term let where the owner does not use it as their principal home; a property where the owner lives and also lets out (principal home lets) remains in C3; the government also introduced parallel permitted development rights from C3 to C5 for properties where prior planning approval is not required — but LPAs can remove this permitted development right in their area by making an Article 4 Direction (which several tourist LPAs are expected to do); (c) The London 90-night rule: in Greater London, the Deregulation Act 2015 s.44 allows a property that is the owner's principal home to be used as short-term accommodation for up to 90 nights per year without planning permission; above 90 nights, planning permission is required; this applies to the owner's principal home only — investment properties let full-time on short-term basis in London require planning permission regardless of the 90-night threshold; (d) Local authority enforcement: LPAs in tourist hotspots (Lake District, Peak District, Cornwall, the Cotswolds) have used planning enforcement powers to require the conversion of short-term let properties to C3 residential use, particularly where high levels of short-term letting are reducing the availability of affordable local housing.

• Use Class C5 (from May 2024, England): properties used primarily as short-term lets where the owner is not the principal resident are in Use Class C5; change from C3 to C5 requires planning permission; LPAs can remove the permitted development right by Article 4 Direction in high-pressure tourist areas
• London 90-night rule (Deregulation Act 2015 s.44): principal home owners in Greater London can let for up to 90 nights per year without planning permission; above 90 nights requires planning permission; investment properties with no principal home use require planning permission for any short-term letting in London
• Pre-May 2024 enforcement: many properties are already in de facto C5 use without planning permission; LPAs may take enforcement action; check the limitation periods (10 years for material change of use other than to C3 dwellinghouse) to assess enforcement risk
• Tourist LPA Article 4 Directions: LPAs in high short-term-let areas (Cornwall, Lake District, Cotswolds) are expected to make Article 4 Directions removing C3-to-C5 permitted development rights; planning permission will then be required for any new short-term let conversion
• Tax is not planning: HMRC furnished holiday let (FHL) status (before abolition in April 2025) was a separate tax concept from planning use class; achieving FHL tax status did not mean the property had planning permission for the relevant use — planning compliance is a separate check

Frequently asked questions