Converting a family home into a house in multiple occupation is a planning question that many landlords get wrong — because the answer changed in 2010, Article 4 Directions have made it more complex since, and many areas now require planning permission where they previously did not.
Converting to a small HMO of up to 6 occupants may be permitted development. In an Article 4 area, or for a large HMO of 7 or more occupants, planning permission is always required.
A single family dwelling is Use Class C3. A small HMO of 3 to 6 unrelated occupants is Use Class C4. A large HMO of 7 or more unrelated occupants is Sui Generis. The change from C3 to C4 is permitted development under Class L of Part 3 of the GPDO unless an Article 4 Direction has removed that right. The change to Sui Generis always requires planning permission.
Since 2010 many councils in England have introduced Article 4 Directions removing the permitted development right to convert from C3 to C4. This means that in a large and growing number of areas — most major university cities and many urban authorities — any conversion to an HMO requires full planning permission. The list of Article 4 areas grows regularly. Always check before assuming C3-to-C4 is permitted development.
Converting from C3 to C4 (permitted development in non-Article 4 areas) then operating with 7+ occupants is an enforcement risk — the Sui Generis threshold is crossed without permission. HMO licensing under the Housing Act 2004 is also required separately from planning permission — licensing does not substitute for planning.
Standard searches check the public register. We go further — querying live portals, blocked legacy systems, pre-merger authority databases, committee PDF archives, Land Registry title constraints, and comparable decisions across your postcode cluster. What we retrieve determines what you know before you build, buy, or appeal.