Turning a family house into a supported living home for up to six people does not need planning permission. Yet about one in four of the certificate applications we reviewed was refused. Not because the law was against them, but because the council was not convinced the home really worked the way the application said it did.
November 2026 · Mustafa Bashkal · 9 min read
Last verified: 5 November 2026 against council decisions, the Use Classes Order, the Town and Country Planning Act 1990 and GOV.UK.
What C3(b) actually is
Use Class C3 is the dwellinghouse class. It has three parts:
- C3(a): a house lived in by a single person, or by people forming a single household, such as a family.
- C3(b): a house lived in by not more than six residents living together as a single household where care is provided for residents.
- C3(c): up to six people living together as a single household where no care is provided.
"Care" has a specific legal meaning. It is personal care for people who need it because of old age, disablement, past or present dependence on alcohol or drugs, or past or present mental disorder. Housing support on its own, such as help with bills, tenancy sustainment or occasional check-ins, does not automatically count. Councils look at what care is actually delivered, and by whom.
It helps to see where C3(b) sits next to the uses it is most often confused with:
| Use | What it is | Planning permission from a family house? |
|---|---|---|
| C3(b) | Up to six residents, one household, care provided | No. A change within the same class |
| C2 | Residential institution: care home, children's home without a resident carer, larger supported schemes | Usually yes, where the change is material |
| C4 | Small HMO: 3 to 6 unrelated people sharing, no care | Yes wherever an Article 4 direction applies, which is most of London |
| Sui generis | Large HMO (7 or more), hostels | Yes |
Why no planning permission is needed
Section 55(2)(f) of the Town and Country Planning Act 1990 says that changing from one use to another within the same use class is not development. C3(a) and C3(b) are both in Class C3. So a family house becoming a C3(b) home is not development at all, and planning permission is not required.
That has two important consequences:
- Article 4 directions are irrelevant. Many London councils have removed the right to turn a house into a small HMO without permission. That restriction applies to permitted development. A change within C3 is not development in the first place, so Article 4 does not touch it.
- Planning policy is not the test. HMO concentration limits, minimum floorspace thresholds and local design policies do not decide whether a house is lawfully in C3(b). The question is one of fact and law.
This is the same everywhere in England. The use classes and the certificate process are national law. What varies from council to council is how hard they test the evidence.
So why apply for anything?
Because "no permission needed" is only worth something if you can prove it. A Lawful Development Certificate is the council's formal confirmation that the use is lawful. Without one:
- Neighbours or the council can allege an unauthorised HMO or care home, and you are defending your position after the event.
- Lenders, buyers and their solicitors have nothing to rely on.
- Commissioners and partners asking about planning status get an opinion rather than a certificate.
There are two kinds, and choosing the right one matters:
- Proposed use (section 192): the house is a family home now and the C3(b) use has not started. This is the usual route when buying or converting. The statutory fee is half the equivalent planning application fee. See our guide to the Lawful Development Certificate (Proposed Use).
- Existing use (section 191): the C3(b) use is already running and you want it confirmed. See our guide to the Certificate of Lawfulness (Existing Use).
Not to be confused with a "ten-year" certificate
This is the most common misunderstanding we see. Many people know existing-use certificates as the way to regularise an HMO or a flat conversion that has been running without permission for long enough to become immune from enforcement. That route is about time: proving years of continuous use.
A C3(b) certificate is different. It does not depend on how long the use has run. If the house was lawfully a family home, the move into C3(b) never needed permission, so there is no clock to beat. What has to be proved is that the house is genuinely being used, or will be used, as C3(b). Applying the "years of use" approach to a C3(b) case, or the other way round, is a quick route to a refusal.
Buying or converting a house for supported living? Send us the address before you commit. We will tell you whether the house and the way it will run are likely to stand up as C3(b).
020 3740 7041 · info@bashkal.com · Request a C3(b) property review
What 139 council decisions show
We reviewed 139 C3(b) certificate decisions made by London councils, reading the officer reports behind the refusals. Of the applications that had been decided, about one in four was refused. Very few were refused because the law was against them. They were refused because the council was not satisfied, on the evidence, that the home was what the application said it was.
The reasons fall into a small number of patterns:
1. Not enough evidence of how the home runs. By far the most common reason. The application repeats the wording of the use class but says little about who lives there, what care they receive, who provides it, or how the household functions day to day. Officers cannot certify what they cannot see.
2. Too many people in the house. The limit is six residents. Councils have counted staff who sleep at the house towards that number, so six residents plus a live-in carer can tip a house over the line.
3. Children's homes without a resident adult. In a leading case, the High Court held that children looked after only by staff on shifts did not form a household with them. Following that, where the adults work shifts and go home, councils treat a children's home as C2 rather than C3(b), and at least one council has tightened its approach since early 2025. Where a carer lives in, C3(b) can be available.
4. A layout that reads like an HMO. Bedrooms with their own cooking facilities, a kitchen on every floor, or locks and numbers on bedroom doors all suggest separate households rather than one. Officers notice.
5. A history that contradicts the claim. Councils cross-check their own records. A previous HMO licence application, rooms advertised to let individually, or an enforcement history can outweigh a well-written statement.
6. Building work bundled in. Extensions and alterations put into the same certificate application have their own tests. Where those fail, they can take the whole application down with them.
On the other side, the applications that succeed tend to show the same things clearly: residents who genuinely need care, a household that lives together, shared kitchen and living space, and an operation that matches the description from start to finish. For adults, the courts have accepted that carers do not have to live in for the residents to form a household; that is a question of fact in each case.
Planning is only half the question: licensing
A C3(b) certificate deals with planning. It says nothing about HMO licensing, which is a separate regime under the Housing Act 2004.
The two use the word "household" differently. In planning, unrelated residents can form a single household. Under the Housing Act, a household generally means members of the same family, so unrelated residents can count as separate households. Depending on how the house is managed and by whom, a C3(b) home can still need an HMO licence, and some arrangements are exempt from licensing altogether. It is worth getting this right at the same time as the planning position, because a licence application describing the house as an HMO can undermine a C3(b) case.
Watch item. The Supported Housing (Regulatory Oversight) Act 2023 allows councils to license supported exempt accommodation. The government set out its approach in June 2026, with consultation on the detailed regulations expected later in 2026. We will update this article when the rules are published.
Doing it properly
C3(b) has picked up a poor reputation in some quarters, and some of it is earned. A minority of operators have used the label to fill ordinary houses with people who receive little or no real care, and to avoid the rules that apply to HMOs. That is why councils test certificate applications closely, and why the government has legislated for closer oversight of supported housing.
A genuine C3(b) home is a care setting, with real legal responsibilities:
- Where staff provide personal care, the care provider must be registered with the Care Quality Commission. A children's home must be registered with Ofsted.
- The residents are often vulnerable. Safeguarding, fire safety and the landlord's repair duties all apply in full.
- The care has to be real: planned, delivered and recorded, not a line in a tenancy agreement.
- Supported exempt accommodation is coming under national standards and local licensing through the Supported Housing (Regulatory Oversight) Act 2023.
None of this should put off a provider who runs a home well; it is what a good provider does already. Our position is simple. We act for owners and operators who intend to run homes properly, and we will tell you plainly if a scheme does not genuinely fit C3(b). That is also the approach most likely to get a certificate.
Five common pitfalls
- Calling it a care home. The language in an application matters. Describing a C3(b) home as a care home, a facility or a scheme invites the council to treat it as C2.
- Applying under the wrong section. Existing and proposed certificates are decided differently. Mixing them, or describing a proposed use in the present tense, has sunk applications.
- Assuming the operator's registration settles it. Registration with a care or children's regulator is a separate regime. We have seen a council give it no weight on the planning question.
- Letting the house as an HMO first. If a house has been let by the room, that history has to be dealt with before a C3(b) case will stand up.
- Thinking the certificate is the end of it. A certificate protects only the use it describes. If the house later runs as individual lets, or with more than six people, the protection falls away.
Our take
C3(b) is one of the few routes into specialist housing that needs no planning permission, which is exactly why councils look at it closely. The law is clear and on your side. Whether you get a certificate comes down to whether the house, the layout and the way the home runs genuinely match the use class, and whether the application proves it. We would always rather look at a house before you buy or apply than after a refusal.
020 3740 7041 · info@bashkal.com · Request a C3(b) property review
Related reading: Lawful Development Certificate (Proposed Use) · Certificate of Lawfulness (Existing Use) · Buying a house for supported living · HMO Conversion in London: the complete 2026 guide · HMO enforcement is tightening
Frequently asked questions
Do I need planning permission to use a house for supported living?
Not if the use falls within Class C3(b): no more than six residents living together as a single household and receiving care. A change from a family house (C3(a)) to C3(b) is within the same use class, so it is not development and needs no planning permission. A Lawful Development Certificate confirms the position.
Does an Article 4 direction stop a C3(b) home?
No. Article 4 directions remove permitted development rights, such as the right to change a house into a small HMO. A change from C3(a) to C3(b) is not development at all, so an Article 4 direction does not apply to it.
What is the difference between C3(b) and C2?
C3(b) is a house where up to six residents live as a single household and receive care. C2 covers residential institutions, such as care homes, where the residents do not live together as an ordinary household. Moving from a family house into C2 usually needs planning permission; moving into C3(b) does not.
Do staff count towards the six-resident limit?
Staff who live at the house can. Councils have refused certificates where residents and live-in staff together exceeded six. Staff who work shifts and do not live there are not residents.
Does a C3(b) home need an HMO licence?
It can. Planning and housing law define "household" differently, and unrelated residents can be separate households under the Housing Act 2004 even when they are one household for planning. Whether a licence is needed depends on how the house is managed and by whom, and some arrangements are exempt.
Is a C3(b) certificate the same as a ten-year certificate?
No. Ten-year and four-year certificates prove that an unauthorised use has become immune from enforcement over time. A C3(b) certificate does not rely on time: it proves that a use within Class C3 is lawful, which can be the case from day one.
Sources: Town and Country Planning Act 1990, sections 55, 191, 192 and 195; Town and Country Planning (Use Classes) Order 1987, as amended, Article 2 and Class C3; Housing Act 2004, sections 254 and 258; North Devon DC v First Secretary of State [2003] EWHC 157 (Admin); R (Crawley BC) v First Secretary of State and Helberg [2004] EWHC 160 (Admin); Supported Housing (Regulatory Oversight) Act 2023; 139 C3(b) certificate decisions by London councils reviewed by Bashkal, to November 2026. General guidance only, not advice on a specific property; case examples de-identified. Verified 5 November 2026.
