A planning expert has highlighted that new class order legislation calling for property investors to apply for  consent when opening a new house in multiple occupation (HMO) may be a misinterpretation of the rules and planners may not have the right to refuse the proposal.

This could leave the way open for HMO landlords to switch family homes to houses in multiple occupation (HMO) without applying for planning permission.

The concept also makes a mockery of government attempts to control the numbers of shared homes for students.

Writing in Planning Magazine, Stephen Ashworth explains use classes order rules only require permission for “development” that includes material changes of use and that the legislation says a change of use in each class is deemed not to be development.

In April, a new use class C4 was created for HMOs – with standard residential homes classified as C3.

Councils have widely interpreted this as meaning new HMOs switching from C3 use to C4 use need planning permission.

The rules do not say that permission is required for changes between use classes, although there is a commonly held misapprehension that permission is always required for such changes, wrote Mr Ashworth.

He cites a government circular (05/2010) to support his view, quoting the document ’simply notes that planning permission “may” be required if there is a material change when a property changes between different use classes’.

A recent planning appeal decision (DCS Number 100-067-072) concerned continued use of a home as an HMO.

Mr Ashworth wrote: “The inspector found no evidence to support the assertion that HMO residents are intrinsically more disposed to make more noise than occupiers of other property types, particularly families with children.

“Whether a dwelling is occupied by a family or a number of unrelated people does not alter the nature of the use.

“This view is plainly right and will make it difficult to enforce against changes in occupation covered by the new use classes.

“If a large family including adult children with cars occupy a house and then rent it out to a similar number of unrelated individuals, is that really likely to lead to a genuine change in use? The external impacts are likely to be largely the same.

“Similarly, if a seventh person joins a group house, are the impacts likely to change materially? How long does the additional person have to stay for the impacts to become material? Is it really a material change of use if one of the occupants starts living with her boyfriend?

“How will occupants and their relationships be monitored?”