An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. Isleworth is 10 miles west of London. We price extensions for extra rooms there against England’s HMO rules and the council’s written HMO standards, so work is planned to the standard an inspection looks for.
- Area
- Greater London, England
- Postcodes
- TW3 and TW7
- Location
- 10 miles west of London
- Pricing region
- London
What do extensions for extra rooms in Isleworth involve?
- Foundations, structure and roof
- Planning route check and drawings
- Ensuite drainage and extraction
- Party wall coordination where needed
- Heating, insulation and glazing
Which rules apply in Isleworth?
Extensions for extra rooms in Isleworth must satisfy national law for England, the council’s written HMO standards and, where walls, drainage or fire separation change, the building rules. In short:
- 7 or more sharers is a sui generis large HMO and normally needs planning permission.
- A conversion can be a material change of use under the building regulations, so confirm with building control before work starts.
- Smoke alarms on every storey with living accommodation and CO alarms by fixed combustion appliances (other than gas cookers) are required by law.
- 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 Isleworth?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Single-storey extension, about 15 m² | £35,000 – £60,000 | £44,800 – £76,800 | project |
| Single-storey extension per m² | £1,800 – £4,000 | £2,300 – £5,100 | m² |
Use these as a starting point for budgeting. Access, condition and the council’s requirements in Isleworth can move the figure either way, which is why we quote after seeing the house.
How long does it take?
Typical time on site: 8–14 weeks. We agree the programme with you before starting and send photo updates as the work progresses.
When do Isleworth landlords need it?
Landlords in Isleworth most often ask us for this when:
- A kitchen too small for the number of sharers
- Adding a ground-floor room
Questions about extensions for extra rooms in Isleworth
Will the extension affect neighbours?
Possibly, if it is on or near a boundary. Party wall procedures may apply in England and Wales.
Which postcodes in Isleworth do you work in?
All of them, including TW3 and TW7, and the surrounding parts of Greater London.
Does a shared house in Isleworth 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 Isleworth?
Our guide ranges for London 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 Isleworth
- Hounslow · 1 mi
- Heston · 2 mi
- Richmond · 2 mi
- Southall · 3 mi
- Hanworth · 3 mi
- Feltham · 4 mi
- All of Greater London
Other HMO services in Isleworth
- Loft conversions for extra rooms in Isleworth
- Communal kitchen refits in Isleworth
- Layout changes and room reconfiguration in Isleworth
- Large HMO conversions (7+ sharers) in Isleworth
- Ensuite installation in Isleworth
- House to HMO conversion in Isleworth
- HMO fire safety upgrades in Isleworth
- Full HMO refurbishment in Isleworth