Article 4 Directions: What HMO Landlords Need to Know
RealYield Team
Property Analyst
Whether you are buying a house to convert or already running an HMO, Article 4 Directions are one of the most important planning rules you need to understand. Get them wrong and you could acquire a property you cannot legally use the way you planned.
In much of England, converting a family home into a house in multiple occupation requires no planning permission at all. Article 4 Directions change that. They exist across most major cities and a growing number of university towns, and landlords who do not check before buying are taking a significant financial risk.
What an Article 4 Direction Is
An Article 4 Direction is a direction made by a local planning authority under Article 4 of the Town and Country Planning (General Permitted Development) (England) Order 2015. Its effect is to remove a specific permitted development right in a defined area.
In the context of HMOs, the relevant permitted development right allows a change of use from a dwellinghouse (Use Class C3) to a small house in multiple occupation (Use Class C4). Under normal rules, this change can happen without any planning application. An Article 4 Direction removes that right.
Once a direction is in place, converting a C3 property to a C4 HMO requires full planning permission. You must submit an application to the local planning authority, which will assess it against local policy, housing mix targets, and the existing concentration of HMOs in the neighbourhood. There is no automatic approval. Permission can be refused.
Source: Town and Country Planning (General Permitted Development) (England) Order 2015, Article 4; legislation.gov.uk [verified June 2026].
What It Does Not Do
This is where landlords frequently misunderstand the rule.
An Article 4 Direction only restricts new conversions. It does not retroactively affect HMOs that were already lawfully operating before the direction came into force. If a property was an established HMO before the direction took effect in that area, it retains its lawful use. The direction cannot require existing landlords to apply for retrospective permission.
This distinction matters when buying. If you are acquiring an HMO with a planning history that confirms lawful C4 use prior to the Article 4 Direction, that use is established and protected. If you are buying a C3 property and intending to convert it, the direction means you will need planning permission first.
Where Article 4 Directions Apply
Many of the UK's major cities and university towns have Article 4 Directions in place for C3 to C4 conversions. Coverage varies: some are borough-wide or city-wide, others cover specific wards or postcodes.
Among the councils with confirmed Article 4 Directions:
- Manchester: city-wide direction in place
- Birmingham: city-wide direction, in force since June 2020
- Bristol: directions cover multiple areas, with additional coverage expanded in 2026
- Leeds: partial coverage across a number of wards
- Nottingham: Article 4 Direction in place
- London boroughs: directions in place across many boroughs including Haringey, Merton, Tower Hamlets, Wandsworth, Lambeth, and Bexley
Frequently Asked Questions
Do I need planning permission to convert a house to an HMO?
It depends on two things: the size of the HMO and whether an Article 4 Direction applies in that area. Converting a C3 dwellinghouse to a small HMO (Use Class C4, 3 to 6 people) is permitted development nationally, meaning no planning permission is required, unless a local authority has put an Article 4 Direction in place. Where an Article 4 Direction exists, planning permission is required before conversion. For large HMOs with seven or more occupants (sui generis), planning permission is always required regardless of location.
Does an Article 4 Direction affect existing HMOs?
No. An Article 4 Direction only restricts new conversions. If an HMO was lawfully in operation before the direction came into force, it retains its established use and does not need to seek retrospective planning permission. When buying an existing HMO, confirm that the lawful use as an HMO was established before the Article 4 Direction took effect in that area.
Is HMO licensing the same as planning permission?
No, they are separate requirements administered by different parts of the council. Planning permission relates to the use class of the property and is managed by the planning department. HMO licensing relates to how the property is managed and is administered by the housing authority. You need both. Holding an HMO licence does not confirm planning compliance, and obtaining planning permission does not mean you are licensed to operate.
What is the difference between a C4 HMO and a sui generis HMO?
Use Class C4 covers small HMOs occupied by three to six unrelated people sharing basic amenities. Sui generis covers large HMOs with seven or more occupants. C4 is the use class relevant to Article 4 Directions, because the permitted development right that Article 4 removes is specifically the change from C3 (dwellinghouse) to C4 (small HMO). Sui generis always requires planning permission regardless of whether an Article 4 Direction is in place.
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