The Town and Country Planning (Use Classes) Order 1987 (as amended) is intended to be a deregulatory mechanism which removes the need for planning permission for changes between certain specified uses by grouping into classes land uses which have similar implications for local amenity. The Use Classes Order defines dwelling houses under the C3 use class as houses used by a single person, any number of persons living together as a family, or by no more than six people living together as a single household.
Where a planning application is required, local planning authorities will be able to assess the application against the relevant policies in their Development Plan taking into account any other material considerations.
The current definition of a dwelling house implies that up to six people living together as a single household should not, prima facie, be considered as a HMO. However local planning authorities may determine individual cases on the basis of “fact and degree” and may decide that a dwelling with fewer than six people living together other than as a single household constitutes a HMO.