In short: An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. Across Devon, the work is planned around England’s HMO rules and the standards the local council publishes.
- Nation
- England
- Pricing region
- South West
- Postcode areas
- EX, TQ, PL, DT
- Main towns
- Plymouth, Exeter, Paignton, Torquay, Newton Abbot
What do extensions for extra rooms in Devon involve?
- Fire separation and detection extended to the new space
- Building control completion
- Heating, insulation and glazing
- Kitchen or bedroom fit-out
- Ensuite drainage and extraction
- Planning route check and drawings
Which rules apply in Devon?
- 7 or more sharers is a sui generis large HMO and normally needs planning permission.
- 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.
- A conversion can be a material change of use under the building regulations, so confirm with building control before work starts.
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 Devon?
| 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 Devon
Questions about extensions for extra rooms in Devon
Do you handle building control?
Yes, from application to completion certificate.
Will the extension affect neighbours?
Possibly, if it is on or near a boundary. Party wall procedures may apply in England and Wales.
Do you carry out extensions for extra rooms across Devon?
Yes, across the whole of Devon, including Plymouth, Exeter, Paignton.
Who licenses HMOs in Devon?
HMOs in Devon are licensed by the local council for the address. Where an area has several councils, each runs its own licensing and planning policies.