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What is Use Class C3?
Last verified 31 October 2026
Use Class C3 is the planning use class for a dwellinghouse. In England it covers use by a single person or people who form a single household, and by up to six residents living together as a single household with or without care, other than a use within Class C4.
Why it matters to landlords
Most buy-to-let houses let to one family or one couple are Class C3. The line between C3 and C4 is whether the residents form a single household or are an HMO under section 254 of the Housing Act 2004. Three unrelated sharers who each rent a room are usually not one household, which points to C4 for planning, regardless of whether a licence is required.
The wording matters when you change who lives there. Letting the same house to a family one year and to sharers the next can move it from one class to the other. Moving between purposes in the same class is not development; a move between classes may need a planning decision, so check with the planning team. The Wales version of Class C3 has an added 183 day occupancy condition, so do not assume the England text applies. Keep a note of how the property was used when you bought it.
Example
Chloe owns a three-bedroom house in Bristol that she has let to a couple with two children for six years. In March 2027 she wants to let it to three working adults on separate agreements. She asks the council in writing whether that moves the house from Class C3 to Class C4 and notes the answer before advertising.