In short: An HMO loft conversion adds one or two letting rooms, often with an ensuite, in the roof space. In Gwynedd we survey first, price each item separately and hand over the certificates and photos a council asks for.
- Nation
- Wales
- Pricing region
- Wales
- Postcode areas
- LL, SY
- Main towns
- Bangor (Gwynedd)
What do loft conversions for extra rooms in Gwynedd involve?
- New stair within the protected route
- Dormer or roof windows
- Feasibility and head-height check
- Building control sign-off
- Fire doors and extended alarm system
- Planning or permitted development check
Which rules apply in Gwynedd?
- 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.
- England’s national room sizes do not apply in Wales; councils set their own room standards.
- Landlords must register with Rent Smart Wales, and those who manage their own lets need a Rent Smart Wales licence.
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 loft conversions for extra rooms cost in Gwynedd?
| Item | UK typical | Local guide | Per |
|---|---|---|---|
| Dormer loft conversion, about 30 m² | £40,000 – £60,000 | £37,600 – £56,400 | project |
| Rooflight loft conversion, about 30 m² | £22,500 – £30,000 | £21,150 – £28,200 | 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 Gwynedd
Questions about loft conversions for extra rooms in Gwynedd
How much head height do I need?
As a rule of thumb, about 2.2 metres at the highest point of the existing roof space before any work. Less can work with a dormer or lowered ceilings.
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 Gwynedd?
Yes, across the whole of Gwynedd, including Bangor (Gwynedd).
Who licenses HMOs in Gwynedd?
Gwynedd council licenses HMOs in its area. Landlords must also register with Rent Smart Wales.
Other HMO services in Gwynedd
- Extensions for extra rooms in Gwynedd
- Large HMO conversions (7+ sharers) in Gwynedd
- Escape routes, emergency lighting and fire stopping in Gwynedd
- Ensuite installation in Gwynedd
- Layout changes and room reconfiguration in Gwynedd
- Fire alarm and detection systems in Gwynedd
- Fire doors in Gwynedd
- Full HMO refurbishment in Gwynedd