An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. Landlords in Horsham (RH12) usually come to us with a council letter, a fire risk assessment or a house they have just bought. We price from whichever you have.
- Area
- West Sussex, England
- Postcodes
- RH12
- Location
- 18 miles north-west of Brighton
- Pricing region
- South East
What do extensions for extra rooms in Horsham involve?
- Foundations, structure and roof
- Ensuite drainage and extraction
- Planning route check and drawings
- Building control completion
- Heating, insulation and glazing
Which rules apply in Horsham?
The rules below are the England-wide position for this kind of work. Councils add their own standards and schemes on top, so we always check the address in Horsham before we price.
- 3–6 unrelated sharers is use class C4; changing from a family house is usually permitted development unless an Article 4 direction applies.
- Building regulations cover structural changes, new partitions, ensuite drainage, fire-resisting construction and notifiable electrical work.
- 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.
- Council standards often step up at 5 and 6 sharers, for example a separate WC at 5 and a second bathroom from 6.
How much do extensions for extra rooms cost in Horsham?
| 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 |
Use these as a starting point for budgeting. Access, condition and the council’s requirements in Horsham can move the figure either way, which is why we quote after seeing the house.
How long does it take?
Allow 8–14 weeks on site for a typical job. Drawings, approvals and long-lead items such as kitchens or fire door sets are booked before we start.
When do Horsham landlords need it?
Typical reasons for this work in Horsham:
- Adding a ground-floor room
- Moving to more sharers with consent
Questions about extensions for extra rooms in Horsham
Do you handle building control?
Yes, from application to completion certificate.
Do you cover all of Horsham?
Yes. We work across Horsham and the RH12 postcode areas, plus the rest of West Sussex. Nearby places we also cover include Crawley, Horley, Haywards Heath.
Does a shared house in Horsham need an HMO licence?
In England, a mandatory licence is needed for 5 or more people from 2 or more households. Smaller HMOs can need a licence where the council runs additional licensing, which is common in towns with many shared houses. Check the council’s website for the address.
How much do extensions for extra rooms cost in Horsham?
Our guide ranges for South East are in the table on this page, and the guide-price tool gives a figure for your house. A fixed written quote follows a free site visit.
Extensions for extra rooms near Horsham
- Crawley · 7 mi
- Horley · 11 mi
- Haywards Heath · 11 mi
- Burgess Hill · 11 mi
- Reigate · 13 mi
- Redhill · 14 mi
- All of West Sussex
Other HMO services in Horsham
- Loft conversions for extra rooms in Horsham
- Communal kitchen refits in Horsham
- Layout changes and room reconfiguration in Horsham
- Large HMO conversions (7+ sharers) in Horsham
- Ensuite installation in Horsham
- House to HMO conversion in Horsham
- Professional and co-living HMO refurbs in Horsham
- Void and between-tenancy refurbs in Horsham