In short: An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. In Wiltshire we survey first, price each item separately and hand over the certificates and photos a council asks for.
- Nation
- England
- Pricing region
- South West
- Postcode areas
- SN, SP, BA, RG
- Main towns
- Swindon, Salisbury, Trowbridge, Chippenham
What do extensions for extra rooms in Wiltshire involve?
- Planning route check and drawings
- Heating, insulation and glazing
- Building control completion
- Foundations, structure and roof
- Ensuite drainage and extraction
- Party wall coordination where needed
Which rules apply in Wiltshire?
- 3–6 unrelated sharers is use class C4; changing from a family house is usually permitted development unless an Article 4 direction applies.
- A conversion can be a material change of use under the building regulations, so confirm with building control before work starts.
- The Fire Safety Order 2005 applies to the common parts of HMOs, enforced by the fire and rescue authority.
- National rules ask for an adequate number of bathrooms, WCs and basins and suitably located kitchens; numeric ratios are set by each council.
- 7 or more sharers is a sui generis large HMO and normally needs planning permission.
Councils in England can add additional licensing and Article 4 directions on top of the national rules. Check the council’s website for the exact address before you buy or start work.
How much do extensions for extra rooms cost in Wiltshire?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Single-storey extension, about 15 m² | £35,000 – £60,000 | £36,400 – £62,400 | project |
| Single-storey extension per m² | £1,800 – £4,000 | £1,850 – £4,150 | 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 Wiltshire
Questions about extensions for extra rooms in Wiltshire
Will the extension affect neighbours?
Possibly, if it is on or near a boundary. Party wall procedures may apply in England and Wales.
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.
Do you carry out extensions for extra rooms across Wiltshire?
Yes, across the whole of Wiltshire, including Swindon, Salisbury, Trowbridge.
Who licenses HMOs in Wiltshire?
HMOs in Wiltshire are licensed by the local council for the address. Where an area has several councils, each runs its own licensing and planning policies.
Other HMO services in Wiltshire
- Loft conversions for extra rooms in Wiltshire
- Communal kitchen refits in Wiltshire
- Layout changes and room reconfiguration in Wiltshire
- Large HMO conversions (7+ sharers) in Wiltshire
- Ensuite installation in Wiltshire
- House to HMO conversion in Wiltshire
- Damp, mould and HHSRS repairs in Wiltshire
- Professional and co-living HMO refurbs in Wiltshire