Commercial to HMO conversion across Cardiff

In short: A commercial to HMO conversion turns space that was never a home, such as upper floors over shops or small office buildings, into shared accommodation. We carry this out across Cardiff, priced against the HMO rules for Wales and the council’s own standards.

Nation: Wales
Pricing region: Wales
Postcode areas: CF
Main towns: Cardiff, Whitchurch

What does commercial and above-shop to HMO in Cardiff involve?

Separate entrance and protected escape route
Sound insulation to floors and party walls
Fire separation between the commercial unit and the homes above
Coordination with planning and building control
New electrics, heating and ventilation
Survey of structure, services and access

Which rules apply in Cardiff?

Councils such as Cardiff and Swansea run additional licensing for HMOs outside the mandatory scheme.
More than 6 sharers is a sui generis HMO and needs planning permission; councils such as Cardiff apply concentration limits.
Building regulations cover structural work, partitions, drainage, fire-resisting construction and electrics; confirm with building control whether the conversion is a material change of use.
Council HMO standards and the fire risk assessment set detection, fire doors and escape routes.
Building regulations sound requirements can apply to conversions and new separating walls and floors.

Cardiff Council: local HMO schemes

Additional licensing	In force in part of the council area Cathays: 1 Feb 2023 to 1 Feb 2028. Plasnewydd had a scheme from 1 Jan 2021; check with Cardiff Council whether it has been renewed.
Selective licensing	No scheme found

Schemes change. Check the council’s current pages for the exact address in Cardiff before you buy or start work. Source: Cardiff Council HMO licensing page, checked 2026-10-31.

How much does commercial and above-shop to HMO cost in Cardiff?

Regional adjustment for Wales. Planning budgets: see our prices page.
Item	UK typical	Local guide	Per
Conversion works per letting room (walls, linings, electrics, decoration; excludes kitchens, bathrooms and fire systems; our estimate)	£3,500 – £6,500	£3,300 – £6,100	letting room
Panel alarm system (Grade A type), larger HMO	£1,750 – £4,500	£1,650 – £4,250	house
Acoustic ceiling or floor upgrade, 12–15 m²	£800 – £2,700	£750 – £2,550	room
Communal HMO kitchen with extra cooking and sink capacity (our estimate from domestic ranges)	£8,000 – £18,000	£7,500 – £16,900	kitchen
Ensuite shower room added to a bedroom	£4,000 – £10,000	£3,750 – £9,400	ensuite

Typical time on site: 12–24 weeks. For a figure for your house, try the guide-price tool.

Commercial and above-shop to HMO by town in Cardiff

Questions about commercial and above-shop to HMO in Cardiff

What about the shop below?

The homes above must be separated from the commercial unit by fire-resisting construction, and the escape route must not pass through the shop. We design the separation as part of the building control application.

Do you work on listed or conservation area buildings?

Yes, with the right consents in place. Older high street buildings often need extra care with windows, fire upgrades and sound insulation.

Do you carry out commercial and above-shop to HMO across Cardiff?

Yes, across the whole of Cardiff, including Cardiff, Whitchurch.

Who licenses HMOs in Cardiff?

Cardiff council licenses HMOs in its area. Landlords must also register with Rent Smart Wales.

Commercial and above-shop to HMO across Cardiff