House to HMO conversion across Greater London

In short: A house to HMO conversion turns a single-family home into a house in multiple occupation: a shared home for unrelated people with private bedrooms and shared kitchen or bathroom space. We carry this out across Greater London, priced against the HMO rules for England and the council’s own standards.

Nation: England
Pricing region: London
Postcode areas: W, E, SW, SE
Main towns: London, Brent, Islington, City of Westminster, Bexley

What does house to HMO conversion in Greater London involve?

A communal kitchen sized for the number of sharers
Layout drawings showing bedrooms, kitchens, bathrooms and the escape route
Decoration, flooring and a handover pack for licensing
Rewiring or upgrades, with an electrical certificate
Fire doors, fire-rated linings and an interlinked fire alarm
Measured survey and room-size check against the licensing standards

Which rules apply in Greater London?

Under the Renters’ Rights Act, civil penalties reach £40,000 for offences such as running an unlicensed HMO.
Licensed HMOs must meet national minimum bedroom sizes: 6.51 m² for one person aged 10 or over, 10.22 m² for two, and 4.64 m² for a child under 10.
National rules ask for an adequate number of bathrooms, WCs and basins and suitably located kitchens; numeric ratios are set by each council.
3–6 unrelated sharers is use class C4; changing from a family house is usually permitted development unless an Article 4 direction applies.
Building regulations cover structural changes, new partitions, ensuite drainage, fire-resisting construction and notifiable electrical work.

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 does house to HMO conversion cost in Greater London?

Regional adjustment for London. Planning budgets: see our prices page.
Item	UK typical	Local guide	Per
Typical 3–4 bed house to a 5–6 bed HMO, all-in	£30,000 – £75,000	£38,400 – £96,000	project
Conversion works per letting room (walls, linings, electrics, decoration; excludes kitchens, bathrooms and fire systems; our estimate)	£3,500 – £6,500	£4,500 – £8,300	letting room
Ensuite shower room added to a bedroom	£4,000 – £10,000	£5,100 – £12,800	ensuite
Communal HMO kitchen with extra cooking and sink capacity (our estimate from domestic ranges)	£8,000 – £18,000	£10,250 – £23,050	kitchen
Interlinked mains alarm system (Grade D type), small HMO (our estimate from installer guides)	£800 – £2,000	£1,000 – £2,550	house

Typical time on site: 6–14 weeks. For a figure for your house, try the guide-price tool.

House to HMO conversion by town in Greater London

Questions about house to HMO conversion in Greater London

How long does a house to HMO conversion take?

Most conversions of a three or four-bedroom house take six to fourteen weeks on site, after drawings and any approvals. Bigger layout changes, extensions or loft rooms add time.

Do I need planning permission to turn a house into an HMO?

It depends on the nation, the council and the number of sharers. In England, three to six unrelated sharers is use class C4, and moving from a family house is usually permitted development unless the council has an Article 4 direction; seven or more normally needs permission. In Wales a change to an HMO always needs permission, in Northern Ireland all new HMOs need it, and in Scotland council policy decides. We check the address before drawings start.

Do you carry out house to HMO conversion across Greater London?

Yes, across the whole of Greater London, including London, Brent, Islington.

Who licenses HMOs in Greater London?

HMOs in Greater London are licensed by the local council for the address. Where an area has several councils, each runs its own licensing and planning policies.