Most HMO conversion advice is a list. The order is what matters, because each step can invalidate the money spent on the ones before it — and the step people leave until last is the one that can stop the project dead.
1. Planning — before you offer
Not after exchange. Not after the builders. Before you make an offer, because this is the only step whose failure mode is "you cannot use the building for this".
- Is there an Article 4 direction covering the address? If so, C3 to C4 needs a full application and refusal is likely, because a council that made one wanted fewer HMOs.
- How many occupiers? Seven or more is sui generis and needs permission everywhere, Article 4 or not.
- Get it in writing. A Certificate of Lawfulness where the position is arguable.
See planning vs licensing. An enforcement notice can require the use to cease; an unlicensed HMO is only ever a financial problem.
2. Your council's standards — before you draw plans
Room sizes and amenity ratios are set locally on top of the national minimums, and they determine how many lettable rooms the building actually has.
The national floor is 6.51 m² for one adult. A council requiring 10 m² turns a six-bed scheme into a four-bed one, and the yield model dies with it. Get the published standards, and remember the 1.5m ceiling rule that removes sloping attic area from the count. See room sizes and amenity standards.
Ask about bathroom and kitchen ratios at the same time. Discovering you need a second bathroom after the first fix is expensive.
3. Building control and fire — during the work
Fire safety is designed in, not added. Retrofitting protected escape routes and fire doors after plastering costs multiples of doing it during.
- Alarm grade and category per LACORS and your council’s standards — specify before first fix.
- FD30 doors with strips, seals and closers to rooms on the escape route.
- Protected escape route, final exit openable without a key.
- Emergency lighting where the route would be unusable in the dark.
See fire safety in HMOs. Building regulations approval is separate from planning and from licensing; it is a third consent.
4. Certificates — before the licence application
The council will ask for them, so have them:
- Gas safety certificate where there is gas — see the CP12.
- EICR, five-yearly — see the five-year cycle.
- EPC, meeting the minimum standard — see EPC minimum standards.
- Fire risk assessment for the common parts.
- Alarm and emergency lighting commissioning records.
5. The licence — before you let, not after
Apply once the property meets the standards. Note that a property is not unlicensed while a valid application is being determined, which is the practical protection — but that only helps if the application went in before occupation.
Which licence: mandatory at five occupiers in two households (plus three storeys in Wales), or additional at three where a council has designated. Check the designation rather than assuming.
6. Tenancies — last
Joint or individual, and the choice changes deposits, liability and possession. See joint vs individual tenancies. In England every new tenancy is periodic under the Renters’ Rights Act; in Wales it is an occupation contract with a written statement due in 14 days.
7. Then the ongoing duties start
The management regulations bind from day one of HMO status, licence or not: your contact details displayed, escape routes clear, certificates producible within seven days of a written request, enough bins.
The order, compressed
Planning → standards → build and fire → certificates → licence → tenancies → ongoing duties.
The two most expensive reorderings are buying before checking Article 4, and drawing plans before reading the council’s room standards. Both are free to avoid and neither is recoverable afterwards.
Start with the council. Every council’s licensing position on record, with the source document.
Information tool, not legal or planning advice.