- Nation
- England
- Pricing region
- South West
- Postcode areas
- PL, TR, EX
- Main towns
- Redruth, Falmouth, St Austell, Truro, Camborne
What do loft conversions for extra rooms in Cornwall involve?
- Dormer or roof windows
- Fire doors and extended alarm system
- New stair within the protected route
- Feasibility and head-height check
- Ensuite where space allows
- Building control sign-off
Which rules apply in Cornwall?
- 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.
- Floor area under a ceiling lower than 1.5 m does not count towards the room size, and many councils set larger sizes.
- Licences last up to 5 years and carry conditions on gas and electrical safety, alarms, room sizes and waste.
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 loft conversions for extra rooms cost in Cornwall?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Dormer loft conversion, about 30 m² | £40,000 – £60,000 | £41,600 – £62,400 | project |
| Rooflight loft conversion, about 30 m² | £22,500 – £30,000 | £23,400 – £31,200 | project |
Typical time on site: 6–10 weeks. For a figure for your house, try the guide-price tool.
Loft conversions for extra rooms by town in Cornwall
Questions about loft conversions for extra rooms in Cornwall
Does adding a loft room change the HMO planning position?
It can. Going from six to seven sharers moves a house into a large HMO in England, which normally needs planning permission. We check before design.
Does a loft room need a fire escape window?
In an HMO the main protection is usually a protected stair and fire doors. The building regulations and fire strategy decide the detail.
Do you carry out loft conversions for extra rooms across Cornwall?
Yes, across the whole of Cornwall, including Redruth, Falmouth, St Austell.
Who licenses HMOs in Cornwall?
HMOs in Cornwall 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 Cornwall
- Extensions for extra rooms in Cornwall
- Large HMO conversions (7+ sharers) in Cornwall
- Escape routes, emergency lighting and fire stopping in Cornwall
- Ensuite installation in Cornwall
- Layout changes and room reconfiguration in Cornwall
- Fire alarm and detection systems in Cornwall
- Student HMO refurbishment in Cornwall
- Fire doors in Cornwall