The single most common use class issue for residential landlords is the C3-to-C4 change for small HMOs (3-6 unrelated people). In areas without an Article 4 Direction, this change is permitted development — no planning permission required. But across a growing number of LPAs (particularly in university cities: Oxford; Cambridge; Bristol; Manchester; Leeds; Newcastle; York; Belfast), Article 4 Directions have removed this PD right, meaning all C3-to-C4 conversions require planning permission regardless of size or location.
From 26 February 2024, England also has a new Class C5 for short-term lets — a property used for short-term accommodation (up to 31 consecutive days, where this is not the occupier's principal home) is now in its own use class. Changing a C3 dwelling to a C5 short-term let is permitted development in most areas, but LPAs in tourist-pressured areas (including St Ives, parts of Cornwall, Lake District, and others) can make Article 4 Directions requiring planning permission for this change. For large HMOs of 7+ people, no use class applies — they are sui generis, and planning permission is always required for the change of use from any other class.
C3 dwelling house, C4 small HMO (PD right; Article 4), C5 short-term let (February 2024), sui generis large HMO, Class Q and Class MA conversion routes
The complete use class framework for residential and investment landlords:
- Class C3 (dwelling house), Class C4 (small HMO — 3-6 people; C3↔C4 PD right; Article 4 Directions), Class C5 (short-term let — from 26 February 2024; C3↔C5 PD right; Article 4 in tourist hotspots) and sui generis (large HMO — 7+ people; always requires planning permission): CLASS C3 — DWELLING HOUSE: a building used as a dwelling house by a single household as their sole or main residence; sub-classes: Class C3(a) — use by a single person or by people living together as a family (including a person caring for children; or a household of up to 6 people as a family unit); Class C3(b) — use by a group of not more than 6 people living together as a single household and receiving care (supported living; care leavers; learning disability housing; people with mental health conditions); Class C3(c) — use by a group of not more than 6 people living together as a single household (with up to 2 unrelated people as members of the household — the position where a couple have 2 lodgers falls into C3(c), provided all 6 people are living together as a single household). THE BOUNDARY BETWEEN C3 AND C4: a dwelling becomes Class C4 when 3 or more unrelated people share it as their only or main residence (but are NOT living as a single household in the C3 sense); key distinguishing factor is whether the occupants form a 'single household' (sharing meals; living communally) or are separate occupiers sharing facilities. CLASS C4 — HOUSES IN MULTIPLE OCCUPATION (SMALL HMO): a HMO occupied by between 3 and 6 unrelated people, each using it as their only or main residence, sharing kitchen, bathroom, or other basic facilities; the Class C4 designation was introduced in April 2010 (Town and Country Planning (Use Classes) (Amendment) (England) Order 2010); PERMITTED DEVELOPMENT RIGHTS (C3↔C4): in most areas, there is a PD right to change from C3 to C4 (and from C4 to C3) — meaning a landlord can convert a C3 dwelling to a small HMO for 3-6 people WITHOUT planning permission; this PD right is in Part 3 Class L of the Town and Country Planning (General Permitted Development) (England) Order 2015 (GPDO 2015); ARTICLE 4 DIRECTIONS REMOVING C3→C4 PD RIGHT: a growing number of LPAs have made Article 4 Directions specifically removing the C3→C4 PD right in their area (typically in defined HMO concentration zones or borough-wide); in Article 4 areas, every C3→C4 change requires planning permission — the LPA will assess the application against its planning policies on HMO concentration; the LPA may refuse permission if the proportion of HMOs in the street or LSOA exceeds a defined threshold (e.g., Oxford: 20% of dwellings in any 100m radius; many LPAs: 10-25% concentration limits); Article 4 LPAs include: Oxford (city); Cambridge (city); Bristol; Manchester; Leeds; Newcastle; York; Nottingham; Southampton; Portsmouth; Brighton; Bournemouth; many others. CLASS C5 — SHORT-TERM LET (from 26 FEBRUARY 2024, England only): introduced by the Town and Country Planning (Use Classes) (Amendment) (England) Order 2024 (SI 2024/244) under powers in the Levelling Up and Regeneration Act 2023 (LURA 2023) s.84; a dwelling used for short-term let accommodation falls into Class C5 where: (a) the accommodation is let to a single household; (b) the letting is for a period of no more than 31 consecutive days; (c) the dwelling is NOT the occupier's only or principal home; PERMITTED DEVELOPMENT RIGHTS (C3↔C5): there is a PD right to change from C3 to C5 (and from C5 to C3) in most areas — a landlord can start using a dwelling as a short-term let (Airbnb; holiday let; serviced accommodation) without planning permission in most areas; ARTICLE 4 DIRECTIONS REMOVING C3→C5 PD RIGHT: LPAs in high-pressure tourist areas can make Article 4 Directions removing the C3→C5 PD right — requiring planning permission for all new C3→C5 changes in their area; Article 4 for short-term lets has been considered or implemented in: St Ives (Cornwall — via earlier Article 4 linked to 2016 Local Plan principal residency policy); parts of Cornwall (Cornwall Council is consulting on Article 4 for C5 in high-pressure coastal communities); Lake District; South Hams (Devon — Salcombe; Dartmouth); Scottish islands. SUI GENERIS — LARGE HMO (7+ UNRELATED PEOPLE): a HMO occupied by 7 or more unrelated people is NEITHER Class C3 nor Class C4 — it is 'sui generis' (in a class of its own); the significance is that sui generis use does NOT benefit from ANY PD rights to change from another use class — planning permission is ALWAYS required for a change to a large HMO use; the LPA determines planning applications for large HMOs against HMO concentration policies and any relevant SPD (Supplementary Planning Document); refusal is common in areas of HMO concentration; also sui generis: hotels (Class C1 hotels are now sui generis — note the separate sui generis status of hotels since the 2020 use class reforms merged most commercial uses into Class E); hostels; boarding houses; amusement centres; casinos; nightclubs; petrol filling stations; vehicle hire businesses; taxi businesses; theatres; drive-through restaurants.
- Class Q PD right (agricultural building to residential — up to 5 dwellings; 865 sqm; 10 years agricultural use; prior approval), Class MA PD right (Class E commercial empty 3+ months to C3 residential — 1,500 sqm; prior approval) and Article 4 Directions (procedure; 12-month notice; compensation liability): CLASS Q — AGRICULTURAL BUILDING TO DWELLING HOUSE (GPDO 2015 Part 3 Class Q): a PD right allowing the change of use of an agricultural building (and associated land) to a Class C3 dwelling house — subject to Prior Approval from the LPA. ELIGIBILITY AND LIMITS: (a) the agricultural building must have been used for agricultural purposes on 24 July 1948 (or since it was first brought into use if later) AND must have been used for agricultural purposes in the period ending 1 July 2021 (or lawfully used for agricultural purposes on that date); (b) the building must have been on an agricultural unit of more than 5 hectares; (c) maximum 5 dwellings from a single agricultural unit (combined maximum); (d) maximum total residential floor area of 865 sqm from a single agricultural unit (combined for all dwellings); each individual dwelling must be up to 465 sqm; (e) the change of use cannot involve new build — only conversion of the existing agricultural structure (structural alterations and reasonable building works to make the building habitable are permitted but new build extension is not); (f) the building must not be in an SSSI; in an area at risk of flooding; in a safety hazard area; within 3km of a protected aerodrome. PRIOR APPROVAL (Class Q): the landlord/developer must apply to the LPA for Prior Approval — the LPA considers: (a) transport and highways impacts; (b) noise impact from existing agricultural operations on the proposed dwelling; (c) contamination risk; (d) flooding risk; (e) the design and external appearance (Class Q permits reasonable external building operations to make the building habitable but the LPA can set conditions); (f) impact on protected species (bats; barn owls; great crested newts); (g) adequate natural light to habitable rooms. CLASS MA — CLASS E COMMERCIAL TO DWELLING HOUSE (GPDO 2015 Part 3 Class MA): a PD right allowing the change of use of a building in Class E (offices; retail; restaurants; gyms; medical centres; light industrial) to residential (Class C3 dwelling house) — subject to Prior Approval. ELIGIBILITY: (a) the building must have been in Class E use on 1 March 2013 (and continuously since); (b) the building must have been VACANT for at least 3 consecutive months before the Prior Approval application; (c) maximum 1,500 sqm of floor space per application (buildings over 1,500 sqm cannot use Class MA); (d) no more than one separate dwelling per storey in the converted building is permitted under certain Class MA provisions (check current GPDO); (e) NOT applicable in: National Parks; AONBs; SSSIs; Safety Hazard Areas; Military Explosives Storage Areas; (f) Article 2(3) land (Conservation Areas) — Class MA DOES apply in Conservation Areas from July 2021 (previously excluded) but with an additional Prior Approval condition on the impact on the character and sustainability of the Conservation Area and on the provision of services from occupied ground floor. PRIOR APPROVAL (Class MA): the LPA considers: (a) transport impacts; (b) contamination; (c) flooding; (d) impacts on the character or sustainability of a Conservation Area (if applicable); (e) natural light to habitable rooms; (f) adequate space standards (NDSS — Nationally Described Space Standard — in London and some other LPAs, even for PD conversions). ARTICLE 4 DIRECTIONS — PROCEDURE AND COMPENSATION: an Article 4 Direction is made by the LPA under Article 4 of the GPDO 2015 to remove specific PD rights in a defined geographic area; PROCEDURE: (a) the LPA resolves to make the Article 4 Direction; (b) the LPA MUST publicise the proposed Direction (notice in a local newspaper; site notice; direct letter to affected landowners); (c) CONSULTATION PERIOD (minimum 21 days for non-immediate Article 4 Directions); (d) after consultation, the LPA confirms the Direction (with or without modifications); (e) a STANDARD Article 4 Direction takes effect 12 MONTHS after the date it is confirmed (to allow landowners time to make planning applications before the Direction takes effect if they intend to exercise the PD right); (f) IMMEDIATE ARTICLE 4 DIRECTION: in exceptional circumstances (e.g., an urgent threat to heritage), the LPA can make an Article 4 Direction that takes effect immediately — but if the Direction takes effect within 12 months of being made and a landowner can demonstrate they have suffered loss because they were unable to exercise the PD right, the LPA may be liable to pay COMPENSATION; COMPENSATION LIABILITY: where a standard Article 4 Direction is confirmed and takes effect after the 12-month notice period, there is NO compensation liability; where an immediate Direction is confirmed, landowners who can show they had a reasonable expectation of exercising the PD right (and were unable to because of the Direction) may claim compensation from the LPA for loss caused
Frequently asked questions
Do I need planning permission to convert a house to an HMO in England?+
For a small HMO of 3-6 unrelated people (Class C4), there is a permitted development right to change from Class C3 (dwelling house) to Class C4 without planning permission in most areas. However, if the LPA has made an Article 4 Direction removing this PD right, you need planning permission for every C3→C4 conversion. Article 4 Directions affecting HMOs are in place in many cities including Oxford, Cambridge, Bristol, Manchester, Leeds, Newcastle, York, and Southampton. For large HMOs of 7+ people (sui generis), planning permission is always required.
What is the new Class C5 short-term let use class?+
Class C5 was introduced from 26 February 2024 (Town and Country Planning (Use Classes) (Amendment) (England) Order 2024) for dwellings used as short-term lets — accommodation let to a single household for up to 31 consecutive days, where this is not the occupier's principal home. There is a PD right to change from C3 (dwelling house) to C5 (short-term let) in most areas — meaning a landlord can start an Airbnb without planning permission. However, LPAs in high-pressure tourist areas (parts of Cornwall; Lake District; South Hams) can make Article 4 Directions requiring planning permission for this change.
What is the Class Q permitted development right for agricultural buildings?+
Class Q (GPDO 2015 Part 3 Class Q) allows an agricultural building to be converted to up to 5 dwellings (Class C3) without planning permission, subject to prior approval. Key requirements: maximum 865 sqm total residential floor area from one agricultural unit (each dwelling max 465 sqm); building must have been in agricultural use for 10 years; no new build (conversion only); prior approval required for transport, noise, contamination, flooding, design, and natural light. Not applicable in SSSIs or areas at high flood risk.
What is the Class MA permitted development right for commercial buildings?+
Class MA (GPDO 2015 Part 3 Class MA) allows Class E commercial buildings (offices; retail; restaurants) that have been vacant for at least 3 consecutive months to be converted to residential (Class C3) without planning permission, subject to prior approval. Maximum 1,500 sqm per building. The building must have been in Class E use on 1 March 2013. Not available in National Parks, AONBs, or SSSIs. Applies in Conservation Areas from July 2021 with an additional prior approval condition on character and sustainability.
- HMO Article 4 Direction — removing C3→C4 permitted development rights →
- Short-term let planning — use class C5 and holiday let permissions →
- Permitted development rights — what requires planning permission →
- Article 4 Directions — procedure and impact on landlord rights →
- House to flats conversion — planning and building regulations →
- Commercial to residential conversion — Class MA prior approval →