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 Dorset, priced against the HMO rules for England and the council’s own standards.
- Nation
- England
- Pricing region
- South West
- Postcode areas
- DT, BH, SP, BA
- Main towns
- Bournemouth, Poole, Weymouth, Christchurch
What do extensions for extra rooms in Dorset involve?
- Building control completion
- Kitchen or bedroom fit-out
- Ensuite drainage and extraction
- Fire separation and detection extended to the new space
- Party wall coordination where needed
- Heating, insulation and glazing
Which rules apply in Dorset?
- 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 Dorset?
| 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 Dorset
Questions about extensions for extra rooms in Dorset
Will the extension affect neighbours?
Possibly, if it is on or near a boundary. Party wall procedures may apply in England and Wales.
Can I extend an HMO under permitted development?
Some extensions to houses are permitted development, but rules differ for HMOs and by nation and council. We check the address before design.
Do you carry out extensions for extra rooms across Dorset?
Yes, across the whole of Dorset, including Bournemouth, Poole, Weymouth.
Who licenses HMOs in Dorset?
HMOs in Dorset 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 Dorset
- Loft conversions for extra rooms in Dorset
- Communal kitchen refits in Dorset
- Layout changes and room reconfiguration in Dorset
- Large HMO conversions (7+ sharers) in Dorset
- Ensuite installation in Dorset
- House to HMO conversion in Dorset
- Commercial and above-shop to HMO in Dorset
- Small HMO conversions (3–6 sharers) in Dorset