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 West Sussex, priced against the HMO rules for England and the council’s own standards.
- Nation
- England
- Pricing region
- South East
- Postcode areas
- RH, PO, BN, GU
- Main towns
- Crawley, Worthing, Bognor Regis, Littlehampton, Horsham
What do extensions for extra rooms in West Sussex involve?
- Heating, insulation and glazing
- Kitchen or bedroom fit-out
- Planning route check and drawings
- Foundations, structure and roof
- Party wall coordination where needed
- Building control completion
Which rules apply in West Sussex?
- 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.
- Fire precautions follow a risk assessment; the LACORS Housing – Fire Safety guide (2008) is guidance, not law, but many councils base their standards on it.
- 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 West Sussex?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Single-storey extension, about 15 m² | £35,000 – £60,000 | £39,200 – £67,200 | project |
| Single-storey extension per m² | £1,800 – £4,000 | £2,000 – £4,500 | 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 West Sussex
Questions about extensions for extra rooms in West Sussex
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 West Sussex?
Yes, across the whole of West Sussex, including Crawley, Worthing, Bognor Regis.
Who licenses HMOs in West Sussex?
HMOs in West Sussex 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 West Sussex
- Loft conversions for extra rooms in West Sussex
- Communal kitchen refits in West Sussex
- Layout changes and room reconfiguration in West Sussex
- Large HMO conversions (7+ sharers) in West Sussex
- Ensuite installation in West Sussex
- House to HMO conversion in West Sussex
- Escape routes, emergency lighting and fire stopping in West Sussex
- Shared bathroom and shower room refits in West Sussex