HMO extensions across Swansea | HMO Refurbishment

In short: An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. We carry this out across Swansea, priced against the HMO rules for Wales and the council’s own standards.

Nation: Wales
Pricing region: Wales
Postcode areas: SA
Main towns: Swansea, Gorseinon, Clydach

What do extensions for extra rooms in Swansea involve?

Fire separation and detection extended to the new space
Building control completion
Planning route check and drawings
Ensuite drainage and extraction
Kitchen or bedroom fit-out
Foundations, structure and roof

Which rules apply in Swansea?

3–6 sharers is use class C4, and in Wales changing a house to C4 always needs planning permission; only C4 back to C3 is permitted development.
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.
Fitness for human habitation rules require mains-powered, interlinked smoke alarms on every storey and CO alarms where there is a gas, oil or solid-fuel appliance.
Kitchen and bathroom ratios are set in each council’s HMO standards.
More than 6 sharers is a sui generis HMO and needs planning permission; councils such as Cardiff apply concentration limits.

Swansea Council: local HMO schemes

Additional licensing	In force in part of the council area Additional licensing in Castle, Uplands, St Thomas and Waterfront wards from 14 Feb 2026 for five years (replaced 2020 Castle/Uplands scheme).
Selective licensing	No scheme found

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

How much do extensions for extra rooms cost in Swansea?

Regional adjustment for Wales. Planning budgets: see our prices page.
Item	UK typical	Local guide	Per
Single-storey extension, about 15 m²	£35,000 – £60,000	£32,900 – £56,400	project
Single-storey extension per m²	£1,800 – £4,000	£1,700 – £3,750	m²

Typical time on site: 8–14 weeks. For a figure for your house, try the guide-price tool.

Extensions for extra rooms by town in Swansea

Questions about extensions for extra rooms in Swansea

Is a kitchen extension worth it?

Often, when the existing kitchen limits how many people the council will allow. A bigger kitchen can unlock an extra room.

Will the extension affect neighbours?

Possibly, if it is on or near a boundary. Party wall procedures may apply in England and Wales.

Do you carry out extensions for extra rooms across Swansea?

Yes, across the whole of Swansea, including Swansea, Gorseinon, Clydach.

Who licenses HMOs in Swansea?

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

Extensions for extra rooms across Swansea