Mandatory, additional and selective licensing: the three schemes
Mandatory licensing, set nationally under the Housing Act 2004, applies to larger HMOs across every London borough: broadly, properties occupied by five or more people forming two or more households sharing amenities such as a kitchen or bathroom. This is the baseline scheme every qualifying property needs, regardless of which part of London it's in, and it sets the national minimum standards for room size and amenities covered later in this guide.
Additional licensing extends mandatory-style requirements to smaller HMOs that wouldn't otherwise need a licence, typically properties with three or four occupants forming two or more households, where a borough has identified a particular concentration of poor housing standards or management issues in its area. Selective licensing goes further still, covering some or all privately rented properties in a defined area regardless of whether they're an HMO at all, usually introduced where a borough has evidence of low housing demand, high deprivation or anti-social behaviour concerns concentrated in specific streets or wards. Whether either scheme applies to a specific property, and on what terms, is set individually by each London borough and can change over time as schemes are introduced, renewed or allowed to lapse, so checking your specific borough's current licensing position is essential rather than assuming last year's requirement still holds, or that a scheme covering a neighbouring borough also applies to yours.
Why licensing varies by borough, and why we won't guess your borough's specifics
It's well established that HMO licensing coverage, fees and specific conditions vary considerably from one London borough to the next. Some boroughs run additional or selective schemes covering a large share of their private rented stock; others operate close to the national mandatory minimum only. Licence fees, renewal periods, and the exact documentation a borough expects at application, an Electrical Installation Condition Report, a valid Gas Safety Record, fire safety evidence, all differ between authorities and can change when a scheme is renewed.
Because these figures and thresholds change over time and differ between all thirty-two boroughs plus the City, this guide deliberately doesn't state specific fees, specific scheme boundaries, or specific renewal dates for individual boroughs, since anything printed here would risk being wrong or out of date for a specific address by the time it's read. The reliable approach is always to check your specific borough's current licensing position directly, through the council's own housing or private rented sector pages, before assuming a figure from a general guide, a neighbouring borough, or a previous licence held on a different property.
National room size standards under mandatory licensing
Underneath the borough-by-borough variation, mandatory HMO licence conditions set national minimum room sizes that apply regardless of which borough a property sits in. A bedroom occupied by one person aged 10 or over needs a minimum floor area of 6.51 square metres, two adults sharing a room need 10.22 square metres, and a room used by a single child under 10 needs at least 4.64 square metres. These are baseline figures set out in the mandatory conditions of licence regulations, and they're a floor rather than a target, some boroughs running additional or selective schemes apply their own room size standards on top of the national minimums, occasionally higher.
Ceiling height affects how these figures get measured in practice, and it's a detail that catches landlords out more often than the headline numbers themselves. Where a room has a sloped ceiling, typically a loft conversion or an attic bedroom in a Victorian terrace, only the section of floor with a ceiling height of at least 1.5 metres usually counts toward the minimum floor area. A room that looks generously sized on a floor plan can measure short once the sloped sections near the eaves are excluded, so measuring against the actual usable footprint, not the overall room dimensions, is what a licensing inspection will actually check.
Amenity requirements: kitchens, bathrooms and facilities
Most councils expect one kitchen for up to five sharing tenants and one bathroom or WC for every four to five occupants, with a minimum number of cooking rings, an oven, a sink and adequate worktop space scaled to how many people are using the kitchen. Inspecting officers count actual fittings against actual occupancy, not intentions or informal arrangements, so a landing with a kettle and a microwave doesn't count as a second kitchen, and a shower room without adequate ventilation or hot water provision doesn't satisfy the bathroom ratio even where it's technically present.
Where an existing property falls short on amenity ratio, the fix usually involves either adding a facility, a second kitchen or shower room fitted into an understairs void or a former coal store is a common solution in Victorian terraces, or reducing the number of licensable bedrooms so the existing facilities cover fewer people. Both routes have knock-on effects worth thinking through before committing: adding a kitchen or bathroom into a space with no existing plumbing or ducting can be a significant piece of building work in its own right, while reducing bedroom count changes the rental income the property was expected to generate, and it's worth having this conversation with whoever manages the licensing side before survey work on the building itself begins.
What an HMO licence inspection actually checks
Fire safety items
Fire doors on bedroom, kitchen and escape route doors, with visible certification evidence and self-closers that fully latch, interlinked mains-powered smoke and heat alarms covering the property to the standard the licence conditions specify, and emergency lighting where the escape route requires it, are all checked directly. Inspecting officers also look at general fire safety housekeeping: whether escape routes are kept clear of bikes, bins or storage, whether service risers and meter cupboards are properly enclosed, and whether any obvious gaps or unsealed penetrations are visible in ceilings or walls along the escape route.
Building fabric and documentation
Room sizes are measured directly against the standards covered above, amenity provision is counted room by room, and officers typically ask to see a current Electrical Installation Condition Report with no outstanding serious faults, a valid annual Gas Safety Record for any gas appliances, and evidence of portable appliance testing on any landlord-supplied white goods in shared kitchens. General condition of the building fabric, damp, disrepair, adequate heating provision, is also assessed as part of the same visit, since HMO licensing covers management and condition standards together rather than fire safety in isolation.
Planning permission alongside HMO licensing
Licensing and planning permission are two separate processes that sometimes get conflated. Converting a house into a smaller HMO, generally up to six unrelated occupants, can fall under permitted development in some areas, but many parts of London sit within an Article 4 direction removing that right, meaning full planning permission is needed even for a fairly modest conversion. Larger HMOs housing seven or more occupants need planning permission everywhere in London regardless of Article 4 status, since that size falls outside permitted development entirely. Article 4 coverage varies block by block in some boroughs rather than applying borough-wide, so it needs checking against the local planning register for a specific address rather than assumed from a general rule. Neither of these planning questions is something we can confirm without checking the specific address, and it's worth resolving before committing to a conversion, since planning and licensing are assessed by different council departments and don't automatically align.
What Lian Construction does and does not do on HMO licensing
We survey a property against the fire safety and room standards that apply, then price and carry out the building works needed to get it licence-ready: fire doors, interlinked alarms, emergency lighting, partition changes to correct undersized rooms, and adding kitchens or bathrooms where amenity ratios fall short. We provide photographs, product certificates and a written specification of completed works, which landlords typically submit alongside a licence application or show an inspecting officer at the first visit.
We don't submit HMO licence applications ourselves, since that involves personal declarations, fit and proper person checks and financial details we're not party to, and it's normally handled directly by the landlord or their letting agent. We also don't confirm a specific borough's current fees, exact scheme boundaries or planning position for an individual address, those come from the council's own published licensing and planning information. What we do is make sure the physical property, once we've finished, actually meets the standard an inspecting officer will check against. Related work is covered by our HMO compliance London, fire safety compliance London and partition walls teams.
Preparing a property for licence application or renewal
Whether you're applying for a first-time HMO licence or preparing for a renewal, a survey against the current standards for your specific borough and scheme is the right starting point, since it tells you exactly what's already compliant and what needs work before you commit a budget or timeline. Our landlord fire safety checklist sets out the fire safety side of this in more detail, fire doors, alarms, emergency lighting and fire-stopping together, as a practical companion to this guide for the licensing side of things.
Get a free, no-obligation quote from Lian Construction
Send the site address, photos if available, and a short description of the work. Lian Construction surveys London properties in Kingston upon Thames and across all boroughs, then provides a clear written quote before any work starts.