Do I need planning permission for an HMO?

Small HMOs may fall within a permitted change in some circumstances, but Article 4 directions in parts of Cornwall remove that, and larger HMOs need a full application. Check the local position before buying with an HMO in mind.

What room sizes are required?

Licensing sets minimum floor areas for sleeping rooms according to occupancy, alongside amenity ratios for kitchens and bathrooms. Cornwall Council's licensing standards are the document to design against, and we lay drawings out to them.

Can you produce licensing plans as well as building regs?

Yes — measured survey, proposed layouts, fire strategy drawings and the plan set licensing officers expect, produced as one coordinated package.

Is a self-contained flat conversion better than an HMO?

Often, in policy terms and at resale, though it costs more to build because each unit needs full compartmentation and Part E performance. The right answer depends on the building and the local rental market.

For landlords · Cornwall

Landlord conversions and HMOs in Cornwall — the drawings licensing officers actually ask for

Converting a house into flats or a licensed HMO is a regulated project with three separate hurdles: planning (a material change of use in most cases), building regulations (fire, sound and means of escape), and licensing (room sizes, amenity ratios and management standards). They are assessed by different people against different criteria.

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The three approvals, and how they interact

Getting one does not get you the others, and designing to satisfy only one usually creates a problem with another.

Planning: change of use, parking, amenity space, and in some Cornish areas policy resisting loss of family housing
Building regulations: Part B fire strategy, Part E sound insulation between dwellings, ventilation and escape
Licensing: minimum room sizes, kitchen and bathroom ratios, and heating and safety standards

Fire strategy is the design driver

In a conversion, the escape route usually determines the plan. Protected stairs, fire doors with correct closers, interlinked detection to the right grade and category, and compartmentation between units are not fittings added at the end — they set where the walls go.

Sound insulation between units

Part E performance between separate dwellings in a conversion is frequently underestimated in older Cornish houses with timber floors. It usually needs a designed floor and wall build-up, and pre-completion testing may apply. Retrofitting it after complaints is far more expensive than designing it in.

Frequently asked

Straight answers.

Do I need planning permission for an HMO?: Small HMOs may fall within a permitted change in some circumstances, but Article 4 directions in parts of Cornwall remove that, and larger HMOs need a full application. Check the local position before buying with an HMO in mind.
What room sizes are required?: Licensing sets minimum floor areas for sleeping rooms according to occupancy, alongside amenity ratios for kitchens and bathrooms. Cornwall Council's licensing standards are the document to design against, and we lay drawings out to them.
Can you produce licensing plans as well as building regs?: Yes — measured survey, proposed layouts, fire strategy drawings and the plan set licensing officers expect, produced as one coordinated package.
Is a self-contained flat conversion better than an HMO?: Often, in policy terms and at resale, though it costs more to build because each unit needs full compartmentation and Part E performance. The right answer depends on the building and the local rental market.

Converting a property to let?

Send us the address and intended occupancy — we will map the three approvals you need.

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