Use Class C4 – Houses in multiple occupation (HMOs)

Use Class C4 of the Use Classes Order 1987 (as amended) is for the use as HMOs

The full description is use of a dwellinghouse by not more than six residents as a “house in multiple occupation”.

Interpretation of Class C4

For the purposes of Class C4 a “house in multiple occupation” does not include a converted block of flats to to which section 257 of the Housing Act 2004 applies but otherwise has the same meaning as in section 254 of the Housing Act 2004.


use class c4

What constitutes a C4 dwelling? 

A dwelling that falls within Use Class C4 is a small shared houses occupied by between three and six unrelated individuals, as their only or main residence, who share basic amenities such as a kitchen or bathroom.

It is vital that some shared facilities exist. Otherwise you risk altering the property into self-contained dwellings and that would require planning permission.

Please note that a bugbear of ours is when people write HMO’s – it is HMOs – there is no apostrophe!  Now we have that out of the way, let’s continue! 🙂 

If an HMO has more than 6 residents and a material change of use has occurred then it will require full planning to become a Sui Generis HMO. If you require assistance with planning permission for a Sui Generis HMO please either request a free fee proposal. Our team of planning consultants are here to help.


Does a C4 HMO have permitted Development Rights?

We believe they do. This is backed up by case law.

A recent High Court ruling (12th July 2022) backs this up. In London Borough of Brent v Secretary of State for Levelling up, Housing and Communities [2022] EWHC 2051 (Admin), the question arose whether buildings in use as C4 HMOs were “dwellinghouses” for the GPDO.

Deputy Judge, Robert Palmer QC, found that HMOs including both small HMO (Use Class C4) and large HMOs (sui generis), are ‘dwellinghouses’.  In determining the meaning of “dwellinghouse” the Deputy Judge set out legal principles including:

  • A dwellinghouse is a unit of residential accommodation which provides the facilities needed for day-to-day private domestic existence (known as the ‘Gravesham test’)
  • Whether any particular building is or is not a dwellinghouse is a question of fact
  • Use Category C3 is not exhaustive of the uses to which a dwellinghouse may be put
  • There is no requirement for a dwellinghouse to be in use by, or akin to, “a single household”. That is a concept confined to Class C3 dwellinghouses
  • It is wrong to say that all C4 HMOs are a dwellinghouses for the GPDO, because a C4 HMO may include flats, which are excluded from the definition of “dwellinghouse” in the GPDO

Therefore we firmly believe that Part 1 of the GPDO extends to HMOs. If you are refused this or need a certificate of lawfulness, please contact us for help.

We also believe that Sui Generis HMOs should also benefit from permitted development rights based on this High Court ruling – don’t you just love case law? (sadly not all go in our favour).


Can C4 dwellings be blocked?

Several local authorities have introduced Article 4s to prevent Class L rights (see below) to allow the movement between C3 dwellings and C4 HMOs. An Article 4 can take a year or more to come into effect, so there ought to be plenty of warning. However make a very careful note of the actual date! Note that Article 4s can block anything. They do not all block C4 HMOs

If an Article 4 is being introduced into an area it is vital that the property has three or more unrelated people on ASTs on the day prior to the Article 4 coming into effect and three or more on the day after. If that is achieved, you will have a legal C4 within an Article 4 area. However we strongly recommend that you obtain a certificate of lawfulness to prove this in the future. Planning Geek can assist with this application to ensure that it is done correctly. Contact us for a fee proposal.

If you have only two or even an empty property when Article 4 comes into effect, you will need full planning! So please be careful.

Note that it is possible for an Article 4 to block C3 to C4, but not C4 to C3 – always ensure that you understand what the Article 4 prevents in your area, otherwise you might slip back to C3 without realising it if left empty for period of time.

A C4 dwelling can also be blocked via other legislation. For example a building converted under Class MA is excluded from being a C4 dwelling via permitted development. Also it can be achieved via full planning.

Finally C4 may be blocked via a condition on a previous planning decision.

You might consider planning permission as an alternative if an Article 4 is blocking HMOs in your area. This might be possible. Although where a local authority has a policy in place to prevent the loss of a family home, that might fail. For example The London Borough of Croydon has Policy DM1.2 of the Croydon Local Plan 2018 which seeks to retain and provide family homes and states that the Council will permit the redevelopment of residential units where it does not result in the net loss of 3 bedroom homes (as originally built) or the loss of homes smaller than 130 sqm. So it is worth checking the local plan to see if your conversion to an HMO is compliant. 


How do I check for an Article 4 in my area?

All Article 4s should be detailed on the website of your local authority. But it is not always easy to find. We normally recommend searching for say ‘<your local authority> article 4’ in Google.

So for example ‘Birmingham City Council Article 4’ (without the single quotes) will give you this page as the top result (not always top, but should be there somewhere). From there we recommend reading the Article 4 Direction, which will tell you exactly what is prevented.

On the page linked above you will find this document – open and read that (or your local authority version) and you ought to find a map and description of what is blocked (Schedule 1 in this example). (click to enlarge map)

It says ‘Development consisting of a change of use of a building from a use falling within Class C3 (dwellinghouses) of the Schedule to the Town and Country Planning (Use Classes) Order 1987 (as amended) to a use falling within Class C4 (houses in multiple occupation) of that Schedule, being development comprised within Class L(b) of Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) Order 2015 and not being development comprised within any other Class.’

Note that this legislation does not block you from going from C4 to C3 – therefore you need to be careful that you do not leave a C4 dwelling with less that three people in it for any length of time. In theory you could drop back to C3 and require full planning to get back to C4! A certificate of lawfulness ought to assist with that. Class L rights are automatic! In the case above Class L(b) is blocked and not Class L(a) which is C4 to C3, Not saying that Birmingham City Council will enforce, but they could do!

If you have an HMO in Birmingham Article 4 area, we strongly recommend that you get a Certificate of Lawfulness now to help prevent you accidentally losing your C4 HMO – contact us for a fee proposal.


Getting planning in an Article 4 area for an HMO?

It is quite possible to get planning in an Article 4 area for HMOsm except where policy exists to prevent it (see above). The criteria for this ought to be published in the local plan. Take our example of Birmingham City Council again. Their policy is contained within DM11 which is a policy within their Development Plan Document. Your local authority ought to have similar.

It says:-

Proposals for the conversion of existing dwellinghouses or the construction of new buildings to be used as Houses in Multiple Occupation (HMO) should protect the residential amenity and character of the area and will be permitted where they:
a. Would not result in this type of accommodation forming over 10% of the number of residential properties within a 100 metre radius of the application site.
b. Would not result in a C3 family dwellinghouse being sandwiched between two HMOs or other non-family residential uses.
c. Would not lead to a continuous frontage of three or more HMOs or non-family residential uses.
d. It would not result in the loss of an existing use that makes an important contribution to other Council objectives, strategies and policies.
e. Would not give rise to unacceptable adverse cumulative impacts on amenity, character, appearance, highway safety and parking.
f. Provide high quality accommodation with adequate living space including:
• Bedrooms of at least 7.5 sq.m. (single) and 11.5 sq.m. (double).
• Communal living space comprising lounge, kitchen and dining space either as distinct rooms or in an open plan format.
• Washing facilities.
• Outdoor amenity space.
• Recycling / refuse storage.

If you comply with the policy there is no reason why you shouldn’t be able to get an HMO in an Article 4 area. However our consultants at Planning Geek are well experienced at obtaining planning in such areas, so please contact us for a free fee proposal. We are here to help.


Can I make my HMO rooms self-contained?

You need to be careful if you do.  What do we mean by this? Essentially can you take a bog standard HMO room perhaps with an en-suite and then add a sink and cooking facilities. If you make them self-contained you are by default perhaps creating separate dwellings within the building. Doing this would require full planning permission.

But what if you created some self-contained. Previously we might have said don’t for the reason above. However a recent High Court decision might be to your benefit.

Welwyn Hatfield Borough Council served an enforcement notice in July 2019 over a two-storey detached house in Hatfield. Conversion works meant it comprised four bedsitting rooms, each self-contained with its own kitchen and bathroom, plus two further bedrooms each with access to a bathroom on the first floor and a kitchen on the ground floor, plus a lounge which was accessible to all residents. Welwyn Hatfield issued the notice on the basis that these arrangements had resulted in the sub-division of the house into five self-contained flats, in breach of planning control.

The inspector visited and concluded it was a house in multiple occupation for not more than six residents, and so fell within the scope of Use Class C4. However the council then appealed to the High Court.

Timothy Mould KC, sitting as a deputy High Court judge, said Whether the four self-contained units, the bedsits, were being used as single dwellinghouses was a question of fact and degree for the inspector to determine on the basis of the evidence before him, including what he observed during his site visit.” He said the law meant it was in principle possible for a house to remain a single dwellinghouse under Use Class C4, even with a mixture of self-contained and shared residential accommodation. The Deputy Judge said. “Nevertheless, he referred also to the existence of communal facilities which were accessible to all occupiers of the house. In the light of those matters, I see no particular difficulty in understanding how and why he came to the conclusion that he did.”

What is very important here is that shared facilities still existed. Had they all been removed then there is no doubt that the decision would have gone against the applicant. Every case is different and we can’t guarantee that yours would be the same. But if you keep shared facilities you might be okay if this judgement is anything to go by.


Permitted Development Changes for Use Class C4

There is one development right to go from or to C4 from/to any other use class.

From another use to Use Class C4:

Class L – C3 dwellinghouse to C4 HMO
Note that once you move a third unrelated person into a C3 dwelling it will automatically become a C4 HMO. No application is required. Although we do recommend a certificate of lawfulness.

From Use Class C4 to another use:

Class L – C4 to C3 dwellinghouse

If you require assistance with planning permission please either request a free fee proposal, or book a Zoom call with Ian, the founder of Planning Geek. Our team of planning consultants are here to help.


Examples for Use Class C4

According to the Planning Geek directory of uses, C4 includes Bungalows, Flats, and houses that are occupied by between three and six unrelated residents and bedsits (assuming they qualify as C4s as above).



Page Updated: 6th June 2024