In short: An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. Across Isle of Anglesey, the work is planned around Wales’s HMO rules and the standards the local council publishes.
- Nation
- Wales
- Pricing region
- Wales
- Postcode areas
- LL
What do extensions for extra rooms in Isle of Anglesey involve?
- Building control completion
- Kitchen or bedroom fit-out
- Heating, insulation and glazing
- Planning route check and drawings
- Fire separation and detection extended to the new space
- Party wall coordination where needed
Which rules apply in Isle of Anglesey?
- 3–6 sharers is use class C4, and in Wales changing a house to C4 always needs planning permission; only C4 back to C3 is permitted development.
- Building regulations cover structural work, partitions, drainage, fire-resisting construction and electrics; confirm with building control whether the conversion is a material change of use.
- Fitness for human habitation rules require mains-powered, interlinked smoke alarms on every storey and CO alarms where there is a gas, oil or solid-fuel appliance.
- Kitchen and bathroom ratios are set in each council’s HMO standards.
- More than 6 sharers is a sui generis HMO and needs planning permission; councils such as Cardiff apply concentration limits.
Welsh councils set their own HMO standards and may run additional licensing. In Wales, changing a house to a C4 HMO always needs planning permission, so check planning first.
How much do extensions for extra rooms cost in Isle of Anglesey?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Single-storey extension, about 15 m² | £35,000 – £60,000 | £32,900 – £56,400 | project |
| Single-storey extension per m² | £1,800 – £4,000 | £1,700 – £3,750 | m² |
Typical time on site: 8–14 weeks. For a figure for your house, try the guide-price tool.
Questions about extensions for extra rooms in Isle of Anglesey
Do you handle building control?
Yes, from application to completion certificate.
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 Isle of Anglesey?
Yes, across the whole of Isle of Anglesey.
Who licenses HMOs in Isle of Anglesey?
Isle of Anglesey council licenses HMOs in its area. Landlords must also register with Rent Smart Wales.
Other HMO services in Isle of Anglesey
- Loft conversions for extra rooms in Isle of Anglesey
- Communal kitchen refits in Isle of Anglesey
- Layout changes and room reconfiguration in Isle of Anglesey
- Large HMO conversions (7+ sharers) in Isle of Anglesey
- Ensuite installation in Isle of Anglesey
- House to HMO conversion in Isle of Anglesey
- Licence condition and schedule-of-works in Isle of Anglesey
- Fire alarm and detection systems in Isle of Anglesey