HMO Room Sizes and Amenity Standards: The Minimums That Fail Applications

A room used as sleeping accommodation in a licensed HMO must be at least 6.51 square metres for one person aged over 10, at least 10.22 square metres for two people aged over 10, and at least 4.64 square metres for a child under 10. A room below 4.64 square metres cannot be used for sleeping at all. Those three figures decide more London licence applications than any other single factor.

Room size is where applications fail quietly. A landlord submits a floor plan, the council measures it, and a room the landlord has been letting for three years comes back as unlicensable. Nothing about the property has changed — the measurement has simply been done properly for the first time. This guide sets out the statutory minimums, how a council actually measures a room against them, where the amenity standards for kitchens and bathrooms sit alongside them, and what happens when a room lands just under the line.

The three statutory minimum room sizes

The minimums are set as conditions attached to every HMO licence granted under Part 2 of the Housing Act 2004, introduced by the Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018 and in force since 1 October 2018. They are not guidance and a council has no discretion to waive them.

The figures are 6.51 square metres for one person aged over 10, 10.22 square metres for two people aged over 10, and 4.64 square metres for one child aged under 10. Any room with a floor area below 4.64 square metres is barred from use as sleeping accommodation outright, whoever is proposed to occupy it.

The distinction between the 6.51 and 10.22 figures matters commercially. A double room let to a couple has to reach 10.22 square metres, not 6.51 — so a 9 square metre room can be let to one adult and cannot lawfully be let to two, regardless of what the tenants would accept or what the room is advertised as. Where a landlord has been taking a couple's rent on a room that measures under 10.22 square metres, the licence application is the point at which that arrangement ends.

How a council actually measures a room

Councils measure usable floor area, not the footprint on the estate agent's plan. Any part of the room where the ceiling height is less than 1.5 metres is disregarded entirely, so a room with a sloped ceiling can measure comfortably above the minimum on paper and fall below it once the low corner is excluded.

This is the single most common surprise in a loft or top-floor room in a London terrace, where the roof pitch eats several square metres of the plan. It is worth measuring these rooms yourself before you apply, from the point where the ceiling reaches 1.5 metres rather than from the skirting board.

Beyond the headroom rule, councils vary in how they treat built-in wardrobes, chimney breasts, en-suite cubicles and the swing of a door. There is no national rule on these, so the borough's own published measurement guidance is the document that decides it. Two boroughs can reach different answers for the same room, and neither is wrong.

The practical consequence is that a professionally drawn floor plan showing measured dimensions and marked headroom lines is worth its cost on any property with rooms near the threshold. An application supported by a plan the council can check is processed faster than one where an officer has to attend and measure before the schedule can be settled.

What the licence itself says about occupancy

An HMO licence is not a general permission to let the property. It specifies the number of rooms in the property suitable for use as sleeping accommodation, and the maximum number of people who may occupy each of those rooms. Exceeding either figure is a breach of the licence, not a matter of tenancy management.

That is why the room schedule is worth reading carefully when the licence arrives. Councils occasionally record a room as single occupancy where the landlord expected double, or omit a room the landlord intended to let. Correcting it later requires a variation of the licence rather than a note to file.

There is also a standing notification duty. The licence holder must tell the local housing authority about any room in the property with a floor area of less than 4.64 square metres. This is a duty on the licence holder, not something the council is expected to discover, and it applies whether or not that room is being used for sleeping.

Amenity standards for kitchens, bathrooms and WCs

Room size is only half the standard. Schedule 3 of the Licensing and Management of Houses in Multiple Occupation (Additional Provisions) (England) Regulations 2007 prescribes standards for the washing and toilet facilities, kitchen facilities and heating that a licensable HMO must provide, scaled to the number of occupiers sharing them.

In practice, councils apply these through a published amenity standard for the borough, which sets out how many WCs, wash hand basins, baths or showers, sinks, cooking rings, ovens, worktop runs and units of fridge and food storage a property needs for a given number of sharers. The ratios step up as occupancy rises, which is why adding a fifth or sixth letting room frequently triggers a requirement for a second bathroom rather than simply a bigger licence fee.

Heating is part of the same schedule and is regularly missed. Every unit of accommodation needs adequate means of space heating — a plug-in electric heater supplied by the tenant does not discharge that duty, and a room heated only by a portable appliance is a straightforward finding at inspection.

The 2007 Regulations sit alongside, not instead of, the ongoing duties in the Management of Houses in Multiple Occupation (England) Regulations 2006, which require the manager to keep the water supply, drainage, common parts, fire precautions and living accommodation in repair and good working order for as long as the property is let as an HMO.

Where borough standards go beyond the national minimum

The 6.51, 10.22 and 4.64 square metre figures are floors, not targets. A council is entitled to set higher standards in its own published amenity and space guidance, and to attach licence conditions reflecting them, and several London boroughs do exactly that for rooms without their own washing facilities or for properties above a certain occupancy.

Because these standards are local, a portfolio spread across London is genuinely subject to different numbers in different boroughs. The room that satisfies one council's standard at 7 square metres may sit below another's threshold for the same use. There is no London-wide answer, and assuming the statutory minimum is the whole test is how landlords with multi-borough portfolios get caught.

Ceiling height and the loft room question

A converted loft raises two separate questions and landlords routinely answer only one. The first is floor area with the sub-1.5 metre headroom excluded. The second is whether the conversion has building regulations approval and a compliant means of escape, which is a fire safety question rather than a space one.

A loft room can pass the space standard and still be unusable as a letting room because the escape route from it does not meet the standard for the property's occupancy — most often where the staircase is open to the ground floor or the room is served only by a fixed ladder. Councils assess space and fire safety together at inspection, so a loft room that fails on either count comes out of the schedule.

Borderline rooms and the conditions councils attach

Where a council finds a room in breach of the room size condition, it must serve a notice specifying a period within which the breach is to be rectified, and that period cannot exceed 18 months. During that period the authority cannot prosecute for that particular breach, which gives a landlord a defined window to reduce the occupancy of the room, reconfigure the layout, or take the room out of use.

That window is narrower than it sounds. Eighteen months is long enough to serve notice and re-let at a lower occupancy; it is not long enough to comfortably obtain planning permission for a rear extension and build it. Landlords who plan to build their way out of a room-size problem generally need to start before the licence application, not after the notice arrives.

The alternative outcomes are a licence granted for fewer occupants than applied for, or a room simply excluded from the schedule of sleeping accommodation. Both are common and both are survivable — what causes real damage is continuing to let a room that the licence does not permit, because that is a breach of a licence condition and exposes the landlord to a civil penalty and to a rent repayment order claim from the tenant in that room.

Overcrowding is a separate test from room size

Statutory overcrowding under Part X of the Housing Act 1985, which applies the room standard and the space standard, is a different regime from the HMO licence room sizes and applies to dwellings generally. A property can comply with one and not the other.

There is a third overlapping test as well. Crowding and space is a hazard assessed under the Housing Health and Safety Rating System in Part 1 of the Housing Act 2004, and a council can take enforcement action on a Category 1 hazard independently of the licence. In other words, meeting the 6.51 square metre condition does not by itself close off every route a council has to act on an overcrowded property.

What to do before you apply

Measure every letting room yourself, excluding any floor area under 1.5 metres of headroom, and write the figures down against each room. Then check them against your borough's published amenity and space standard rather than against the national minimum, and decide the proposed occupancy of each room before the application rather than after.

Where a room falls between 4.64 and 6.51 square metres, the honest position is that it is not a letting room. Marketing it as a small single, or as a study with a bed in it, does not change the licence condition and does not help at inspection.

We check room sizes and amenity provision against the specific borough standard before we submit, so the schedule that comes back on the licence matches the schedule you expected. Our fixed fees are £300+VAT for an additional licence application and £500+VAT for a mandatory licence application — contact us for a free assessment of your property.