What is included in extra rooms and layouts?
Lofts, extensions and layout changes that add or improve letting rooms. Choose a service for the detail, the rules in each nation and guide prices.
Loft conversions for extra rooms
An HMO loft conversion adds one or two letting rooms, often with an ensuite, in the roof space. Adding a storey changes the fire strategy: the new floor needs a protected route down through the house, fire doors and extended detection, and building regulations approval is always needed.
Extensions for extra rooms
An HMO extension adds space to a shared house, usually a ground-floor bedroom with ensuite or a bigger communal kitchen. It needs the right planning route, building regulations approval and a fire strategy that still works for the whole house once the space is added.
Layout changes and room reconfiguration
HMO layout reconfiguration changes the internal plan of a shared house so the rooms, kitchens and bathrooms work together: moving or adding walls, splitting oversized rooms, merging undersized ones, or moving the kitchen off the escape route. Each change is checked against room sizes, the fire strategy and building rules.
Guide prices
| Item | UK typical | Per |
|---|---|---|
| Dormer loft conversion, about 30 m² | £40,000 – £60,000 | project |
| Rooflight loft conversion, about 30 m² | £22,500 – £30,000 | project |
| Single-storey extension, about 15 m² | £35,000 – £60,000 | project |
| Single-storey extension per m² | £1,800 – £4,000 | m² |
| New stud wall and door forming a room, per room (our estimate) | £1,500 – £3,500 | room formed |
| Conversion works per letting room (walls, linings, electrics, decoration; excludes kitchens, bathrooms and fire systems; our estimate) | £3,500 – £6,500 | letting room |
Questions
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.
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.
Can you split a large room into two letting rooms?
If both new rooms meet the size standard, have natural light and ventilation, and the fire strategy allows, yes.