If you are looking to convert a C3 property – that’s a flat or a normal house – to a House in Multiple Occupation (HMO) – that’s a property rented out by at least 3 people who are not from one household but who share certain living facilities (such as a bathroom and/or kitchen) – this page provides some helpful planning advice. 

All flats and normal houses (i.e. residential properties occupied by one “household” – normally a family – and up to 2 lodgers) have a C3 use class. 

HMOs are divided into two use classes according to their size. HMOs occupied by between 3 and 6 unrelated people fall into use class C4. HMOs with 7 or more occupants are considered to be “Sui Generis” – although this is not technically a use class, it functions like one. 

Do I need planning permission to convert my flat or house (C3) to a HMO?

The short answer is that it depends. 

In most cases, you can convert a flat or normal house (C3) to a HMO occupied by no more than 6 people (C4) without any need for planning permission (and vice versa).

The reason for this is that the change of use of a property from C3 to C4 (and vice versa) is a type of permitted development right held by most properties. You can find out more about permitted development rights, including what they are and what sorts of properties hold them – here. 

You should always make sure your property possesses the relevant permitted development right (C3 to C4) before you convert it. 

In the event that your change of use from C3 to C4 is covered by permitted development rights, we would still strongly recommend that you apply to your Local Planning Authority (this is normally your local council) for a Lawful Development Certificate. A Lawful Development Certificate will provide formal confirmation that your change of use is definitely “permitted development” and protect you against potential future enforcement action which can be very costly and inconvenient. You can find out more about Lawful Development Certificates here. 

If your HMO is to be occupied by more than 6 people, you will always need planning permission for it, irrespective of the building’s current use. This means that the change of use of any C3 property to a Sui Generis HMO will always require a formal planning application to be made to the Local Planning Authority (LPA). 

Please be aware that you may also need to apply for other relevant HMO licences from your local council that are unrelated to planning. 

Do I need to submit a planning application to convert my flat or house (C3) to a HMO?

If your change of use of a residential property (C3) to a HMO (C4 or Sui Generis) requires planning permission, you must submit a full planning application to your Local Planning Authority (this is normally your local council). Your Local Planning Authority (LPA) will then assess your planning application and either approve or refuse it. 

In assessing your planning application, the LPA will take account of their local planning policies and any other “material planning considerations” – find out more about these here. 

Although the content of local planning policies will vary, there are certain key planning issues that almost always apply when considering the change of use of a residential property (C3) to a HMO (C4 or Sui Generis) anywhere in England. These are discussed below. 

What are the key planning issues? 

Local planning policies will vary and it is important that your planning application is designed to meet the policies in force in your local area. There are, however, a number of key planning issues that will almost always apply to the proposed change of use of a residential property (C3) to a HMO (C4 or Sui Generis), no matter where the site is located. 

These are:

Effect on character and appearance

“Character and appearance” is the way a place looks, functions and “feels”. 

This includes its buildings (size, height, architecture etc.), its layout (e.g. are buildings close together or far apart?), its uses and activities (e.g. is it a busy town centre or a quiet residential street?).

When it comes to a change of use of a residential property (C3) to a HMO (C4 or Sui Generis), the LPA will mainly be concerned with the:

• Effects of physical development including external and internal changes (such as new windows or partition walls). Is it designed and constructed to a high quality? Is it “in keeping” with the building and surrounding area’s established character and appearance? For example, do any new windows follow the style, position and materials of the building’s existing windows?

• Effects of the HMO’s occupation. For example, would it lead to a significant increase in the site’s occupancy that is likely to disturb families in neighbouring houses? Would it lead to a substantial increase in on-street parking that detracts from the visual qualities of the street? Would it lead to the loss of a family-sized home in an area where the LPA is keen to retain family housing, for example because there is already a severe lack of housing suitable for families? The impact of a HMO is far more likely to be acceptable in densely-built and “highly sustainable” areas, e.g. town centres with very good public transport links.

Effect on parking and highways 

The LPA will consider whether there is enough parking available for the HMO.

Some LPAs have detailed parking standards that tell you the minimum number of parking spaces different sites/buildings should have available. Some LPAs have different standards for HMOs and normal residential properties (C3). 

In most cases, LPAs will expect you to comply with their minimum parking standards. However, exceptions are frequently made in the following circumstances:

• The site is in a town centre or other “highly sustainable” location (e.g. lots of pavements and very good access to public transport); or
• The existing parking situation would not be made worse (e.g. there is currently a deficit of 1 parking space for a C3 use of the building and the deficit for a HMO use of the building would also be 1 space).

If parking is already an issue on the site or in the local area (for example, there is a lack of driveways leading to lots of on-street parking) and the conversion of your building to a HMO would be likely to worsen this (for example, it would increase the site’s occupancy, leading to a similar increase in private car use) then the LPA is likely to refuse the change of use. 

In terms of effects on highways (roads), the LPA will need to be satisfied that the change of use of the building will not cause harm to their safety or proper functioning. This includes consideration of the following matters:

• Will there be a significant increase in traffic?
• Will there be a significant increase in on-road parking (and can the road sustain that)?
• Will there be an increased risk of conflict between drivers and pedestrians?

Effect on residential amenities

The LPA will need to be satisfied that the use of the building as a HMO would not cause unacceptable harm to any nearby residential properties. In areas dominated by family homes, the LPA is likely to place even greater weight on the following matter:

• Is the property’s use as a HMO likely to give rise to antisocial behaviour or other disturbance (such as noise or littering) that would cause a lot of harm to the established residential community?

If your change of use requires physical changes to the property, the effect of these changes on neighbours and nearby residents will also be considered. For example, new windows should not cause a significant loss of privacy to existing homes (due to overlooking etc.).

Standard of accommodation

The LPA will need to be satisfied that the HMO would provide an acceptable standard of accommodation to its residents. 

There are certain standards that all new HMOs throughout England will be expected to meet. For example, a bedroom for 1 occupant aged 10 or over must be at least 6.51 square metres*.

*please be aware that although we make every effort to keep our website up-to-date, HMO standards do change occasionally and you should always check the standards in force at the time of making your application.

The LPA will likely also have local design policies concerning (for example) the size/layout of shared facilities, gardens, bin storage etc. 

Although HMOs are rarely held to the same high standards as normal houses (C3)**, they must still be fit for purpose and support their residents to live happy and healthy lives. 

**For example, because HMOs are unlikely to be occupied by families, LPAs will often allow smaller gardens as there is a lesser requirement for outdoor play space.

What do I need to submit with my change of use planning application?

Your planning application for a change of use of a residential property (C3) to a HMO (C4 or Sui Generis) should normally include:

1. Application form;
2. Planning, design & access statement/s; and
3. Suite of relevant planning drawings:

• Site location plan
• Block plan
• Existing and proposed floorplans
• Existing and proposed elevations.

Other requirements will vary depending on the LPA and its local policies, the site/location and the physical changes required (if any). For example:

• If the change of use requires alterations to the roof, existing and proposed roofplans must be submitted; 
• If the change of use affects a Listed Building or Conservation Area, the LPA is likely to require a Heritage Impact Assessment;
• If the change of use is in an area with high parking pressures, lots of traffic and/or substandard roads, the LPA may request a Transport Statement;
• If the change of use is in flood zone 2 or 3, a Flood Risk Assessment may be requested. 

How can Planning Direct assist with my change of use application?

Planning Direct can assist you with all aspects of your change of use planning application, from start to finish. Our “comprehensive package” includes the following services:

• design guidance
• planning drawings
• planning, design & access statement; and 
• case management*. 

*this means we will submit the planning application on your behalf and then act as your agent throughout the process, liaising with the LPA until a decision is reached. 

You can find more information about these services here.

If you don’t require a comprehensive package (for example, because you are providing your own drawings), we can provide a bespoke selection of the above services at a reduced cost.

In the event that any supplementary reports are required (such as a Flood Risk Assessment, Heritage Impact Assessment etc.), we can either produce these in-house or commission them from an external provider on your behalf. We will always agree this with you beforehand. 

Planning Direct will ensure that your planning, design & access statement is carefully crafted to address all relevant local planning policies and all relevant planning issues (such as those described above). 

How much will it cost?

There are two main expenses that you need to take into account:

1. Preparation and submission of the planning application (including drawings, written statement, case management etc.); and
2. Application fee payable to the LPA.

Currently, the application fee for a change of use of a residential property (C3) to a HMO (C4 or Sui Generis) in England is £462*. 

*please be aware that although we make every effort to keep our website up-to-date, application fees do change occasionally and you should always check the fees in place at the time of making your application. 

At Planning Direct, fees for a comprehensive change of use planning application start from £1195.

Please be aware that in certain circumstances the LPA may request supplementary reports (such as a Flood Risk Assessment, Heritage Impact Assessment etc.) which will attract additional fees. 

Broadly speaking, the fewer physical alterations you need to make to the building in order to change its use to a HMO, the less the cost of the planning application overall. 

Although you are entitled to prepare and submit your own planning application, employing a good planning consultant can save you money in the long run. This is partly because there are various technical requirements that your application must meet in order to even be considered by the LPA. For example, planning drawings must be drawn to particular scales and show specific site/locational features. If it takes you multiple attempts to get this right, you could spend more money overall.