Converting a property into a House in Multiple Occupation (HMO) can be a great investment, particularly in cities like Bristol where demand for rental accommodation is high. However, understanding the planning use classes and navigating the regulations is crucial before you begin any HMO project. Two key use classes that landlords need to be familiar with are Class C4 and Sui Generis, these dictate how HMOs are defined and regulated in the planning system.
In this blog, we’ll explain what these planning use classes mean, the differences between them, how they apply to HMOs, and when planning permission is required. By the end, you’ll have a clearer understanding of how to navigate the planning process for HMO developments.
What Are Planning Use Classes?
The UK’s planning system organizes properties into different categories called Use Classes, as outlined in the Town and Country Planning (Use Classes) Order 1987 (with updates). These classes define what types of activities or occupants a property can host, and they help local councils regulate how land and buildings are used within their area.
For landlords and property investors, understanding these classes is key to ensuring you comply with local planning regulations and avoid potential legal issues.
Use Class C4: Small HMOs
Class C4 refers to small Houses in Multiple Occupation (HMOs), where between 3 and 6 unrelated individuals live together, sharing facilities such as bathrooms and kitchens. This use class is specific to small HMOs and is distinct from standard residential properties (which fall under Class C3).
In most cases, converting a property from Class C3 (Dwelling Houses) to Class C4 (Small HMOs) can be done without the need for full planning permission, thanks to Permitted Development Rights (PDRs). This allows landlords to convert a property into a small HMO without submitting a formal planning application to the local council, provided the property will house no more than six unrelated people.
When Do You Need Planning Permission for Class C4?
While Permitted Development Rights allow for easy conversion in some areas, you must be aware of Article 4 Directions—local planning regulations that restrict these automatic rights. In cities like Bristol, Article 4 Directions have been introduced in several areas to control the density of HMOs.
For example, areas such as Clifton, Redland, and Cotham are covered by Article 4, meaning that even converting a property into a small HMO (C4) will require full planning permission. This policy was put in place to prevent over-saturation of HMOs in certain neighborhoods, which can disrupt the balance of communities, increase pressure on local infrastructure, and affect the quality of life for residents.
Key Considerations for Class C4 HMOs:
- Occupancy Limits: Class C4 is limited to a maximum of six tenants. If you want to house more than six people, the property will fall into a different use class.
- Compliance: Even if planning permission isn’t required, your property must still comply with HMO licensing and building regulations, especially regarding safety and living conditions (such as minimum room sizes and fire safety measures).
- Article 4 Areas: Always check with the local council to see if the property is in an Article 4 area, as this will affect whether or not you need planning permission to convert it into an HMO.
Sui Generis: Large HMOs
Sui Generis is a Latin term meaning “in a class of its own.” Properties that fall under Sui Generis use do not fit into the standard planning use classes, and they include large HMOs.
An HMO with 7 or more unrelated tenants is classified as Sui Generis and does not benefit from Permitted Development Rights. In this case, you will always need to apply for full planning permission to convert a property from Class C3 (Dwelling Houses) or Class C4 (Small HMO) to a Sui Generis HMO.
Planning Permission for Sui Generis HMOs:
Converting a property into a large HMO under Sui Generis requires a formal planning application, regardless of the area in which the property is located. The local council will assess the impact of the development on the surrounding neighborhood, particularly looking at issues such as:
- Impact on the local community: Councils assess whether converting a property into a large HMO will unbalance the housing mix in the area or put strain on local services and infrastructure.
- Parking and traffic: Larger HMOs often mean more occupants and potentially more cars, so councils will consider whether the property has adequate parking or whether it might create traffic problems.
- Living conditions: The council will ensure that the property provides adequate living conditions, including room sizes, kitchen and bathroom facilities, and access to shared spaces.
Licensing and Regulations for Sui Generis HMOs:
Like smaller HMOs, large HMOs that fall under Sui Generis must comply with HMO licensing requirements. This means ensuring that the property meets the following standards:
- Fire Safety: The property must be equipped with fire doors, smoke alarms, and escape routes, and undergo regular fire risk assessments.
- Room Sizes: Rooms must meet minimum size requirements (typically 6.51 square meters for a single occupant).
- Amenities: There must be adequate kitchen and bathroom facilities based on the number of occupants, as well as suitable communal spaces.
Key Differences Between Class C4 and Sui Generis for HMOs
When comparing Class C4 (Small HMO) and Sui Generis (Large HMO), the key difference is the number of occupants. Here’s a summary of the distinctions:
| Feature | Class C4 (Small HMO) | Sui Generis (Large HMO) |
|---|---|---|
| Occupancy | 3 to 6 unrelated tenants | 7 or more unrelated tenants |
| Planning Permission | Not required under PDRs (except in Article 4 areas) | Always required |
| License Requirements | HMO license required if 5+ tenants | HMO license always required |
| Living Conditions | Must meet HMO standards (room sizes, fire safety, etc.) | Must meet stricter HMO standards |
When Do You Need Planning Permission?
To recap, the need for planning permission largely depends on two factors: the size of the HMO (the number of tenants) and the location of the property. Here’s when you’ll need to apply for planning permission:
- Class C4 to Sui Generis: If you are converting a small HMO (with 3–6 tenants) into a large HMO (with 7 or more tenants), you will need planning permission as the property changes to Sui Generis use.
- Class C3 to Class C4: If you are converting a single dwelling into a small HMO, you generally do not need planning permission, unless the property is in an Article 4 area.
- Article 4 Areas: If the property is in an area with Article 4 Directions (like parts of Bristol), planning permission is required even to convert from C3 to C4. Learn more about Article 4 In Bristol here.
Why Planning Permission is Important for HMOs
Planning permission is essential to ensure that the development of HMOs is managed properly, both for landlords and for the community. Councils need to maintain a balance in housing stock, ensure that adequate services are in place, and prevent the negative impact that too many HMOs can have on neighborhoods.
For landlords, obtaining the correct planning permission protects against legal issues and ensures that your property complies with all regulations. Failing to obtain the necessary permissions can result in fines, enforcement notices, and, in some cases, having to revert the property back to its original use.
Navigating the use classes of C4 (Small HMOs) and Sui Generis (Large HMOs) can seem complex, but understanding the basics of when planning permission is required can save you time, money, and stress. Whether you’re developing a small HMO for young professionals or converting a larger property to house multiple tenants, following the right procedures will ensure your project runs smoothly and complies with local planning policies.
Before starting any project, it’s crucial to check with your local council about whether the property is in an Article 4 area, and to understand the planning requirements specific to your project. With the right approach, you can maximize your property’s potential while contributing to a well-balanced housing market. Once you have your HMO, you’ll need to enusure correct management – Front Door Lettings can assist with your HMO management in Bristol.
