The Town and Country Planning (Use Classes) (Amendment)
(England) Order 2010 (SI 2010/653) amended the Town and
Country Planning (Use Classes) Order 1987 in relation to residential properties. It effectively splits the old C3:
Dwellinghouses class into two classes
C3: Dwellinghouses and
C4: Houses in multiple occupation.
From the 6 April 2010 planning permission is needed for any material change of use from C3 to C4.
Advice is contained in Communities and Local Government
Circular 05/2010

Reclassification of use as a result of the amended UCO
Uses that previously fell into the former C3: Dwellinghouses use class will fall into one of the new C3 or C4 use classes.
Reclassification of a use does not amount to development within the meaning of the Town and Country Planning Act
1990.

Class C3. Dwellinghouses
Use as a dwellinghouse (whether or not as a sole or main residence) by:
(a) a single person or by people to be regarded as forming a single household;
(b) not more than six residents living together as a single household where care is provided for residents; or
(c) not more than six residents living together as a single household where no care is provided to residents (other than a use within Class C4).

For the purposes of C3(b) and (c) single household is not defined in the legislation.
There is no limit on the number of members of the single household under C3(a). The limit for C3(b) and (c) is no more than 6 people.
The term ‘dwelling house’ is not defined in this part of the
UCO. The question of whether a particular building is a dwelling house will therefore depend on the facts of that case.
This would not include bed-sitting rooms. The planning unit is likely to be the whole building which would therefore be classified as a HMO.

Class C4. Houses in multiple occupation
Use of a dwellinghouse by not more than six residents as a “house in multiple occupation”.
The new C4 class covers small shared dwelling houses occupied by between 3 and 6 unrelated individuals who share basic amenities.
Small bed-sits properties will be classified as C4.
Properties containing the owner and up to two lodgers do not constitute HMOs for these purposes.
To classify as a HMO a property does not need to be converted or adapted in any way.

Large houses in multiple occupation
Large HMOs - those with more than 6 people sharing – are unclassified by the UCO.
Although the control limit of 6 persons defines the scope of the C3 dwellinghouses and C4 HMO classes, this does not imply that any excess of that number must constitute a breach of planning control. A material change of use will occur only where the total number of residents has increased to the point where it can be said that the use has intensified so as to become of a different character or the residents in relation to C3 no longer constitute a single household.

On 7 September 2010 The Town & Country Planning
(General Permitted Development) (Amendment) (No 2)
(England) Order 2010 (2010 No. 2134) was laid before
Parliament.
The Statutory Instrument will come into force on 1 st October
2010 and will make changes of use from Class C3
(dwellinghouses) to Class C4 (houses in multiple occupation) permitted development.