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Minimum Bedroom Size UK: What the Rules Actually Say

No building regulation sets a minimum bedroom size in your own home. Three other rulebooks do set numbers, and each applies to a different kind of property.

Search for a minimum bedroom size UK figure and you will be given 6.51m2, or 7.5m2, or 70 square feet, usually with no indication of where any of them come from. All three are real numbers from real sources. None of them is a building regulation, and only one of them is likely to apply to the room you are actually asking about.

Here is the honest position for England. If you are converting a loft, dividing a room or refitting a bedroom in a house you live in, there is no minimum bedroom size in the Building Regulations. What the regulations control is escape, ventilation and the stair that gets you there, not floor area. The three sets of numbers people quote come from a planning standard for new build, a licensing regime for shared houses, and a 1985 overcrowding law. Each is set out below with its source, so you can tell which one, if any, binds your project.

1. The nationally described space standard: new build, and only if adopted

This is where 7.5m2 comes from. The nationally described space standard was published in March 2015 with notes added on 19 May 2016. It is a planning standard, not a building regulation, and it applies only to new dwellings, and only where a local authority has adopted it in its Local Plan. The document says so itself: its bedroom, storage and internal area requirements are relevant only in determining compliance with the standard, and have no other statutory meaning or use.

Where it does apply, the bedroom figures are:

  • Single bedroom (one bedspace): at least 7.5m2 and at least 2.15m wide.
  • Double or twin bedroom (two bedspaces): at least 11.5m2.
  • Widths: one double or twin bedroom must be at least 2.75m wide, and every other double or twin at least 2.55m wide.
  • At least one double: a dwelling with two or more bedspaces must have at least one double or twin bedroom.
  • Ceiling height: at least 2.3m for at least 75% of the gross internal area.
  • Low headroom: any area with headroom under 1.5m is not counted in the gross internal area at all, unless it is used solely for storage. Storage space with 900mm to 1500mm of headroom, such as under eaves, counts at half its floor area, and anything under 900mm does not count.
  • Built-in wardrobes: they count towards both the gross internal area and the bedroom floor area, but must not reduce the effective width of the room below the minimums above.

The standard also sets whole-dwelling minimums. A one bedroom, one person flat is 39m2, dropping to 37m2 if it has a shower room rather than a bathroom. A two bedroom, four person home is 70m2 on one storey and 79m2 over two. A three bedroom, five person home is 86m2, 93m2 or 99m2 over one, two or three storeys.

The practical point: if you are extending or converting an existing house, this standard almost certainly does not apply to you. If you are building new, ask your planning officer whether the local plan has adopted it, because that single answer changes the brief.

2. HMO licensing: 6.51m2, and this one is law

If the property is a licensed house in multiple occupation, the numbers are mandatory conditions of the licence under the Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018, in force since 1 October 2018. The licence holder must ensure that:

  • a room used as sleeping accommodation by one person aged over 10 is not less than 6.51m2;
  • a room used by two people aged over 10 is not less than 10.22m2;
  • a room used by one person aged under 10 is not less than 4.64m2;
  • any room with a floor area of less than 4.64m2 is not used as sleeping accommodation at all.

Two details in the regulations matter more than the headline figures. Any part of the room where the ceiling height is under 1.5m does not count towards the floor area, which catches a lot of attic rooms. And the licence holder has a positive duty to notify the council of any room under 4.64m2, which means a small box room is not something you can quietly leave off the plan.

These rules apply to licensed HMOs. They do not apply to a family home, and they are not a general definition of a bedroom.

3. Overcrowding: the 1985 law nobody quotes correctly

This is where the 70 square feet figure comes from, and it is not a minimum room size at all. It is the space standard in section 326 of the Housing Act 1985, which decides how many people may sleep in a dwelling. Two tests run together and the lower answer wins. The floor area test works like this:

  • 110 sq ft or more: 2 people
  • 90 to under 110 sq ft: 1.5 people
  • 70 to under 90 sq ft: 1 person
  • 50 to under 70 sq ft: half a person
  • Under 50 sq ft: not counted at all

A child under one is not counted; a child aged one to under ten counts as half a unit. A room counts as sleeping accommodation if it is of a type normally used in the locality as a living room or a bedroom, which is why a dining room can be pulled into the calculation.

So the honest translation of "the minimum bedroom size is 70 square feet" is: a room under about 6.5m2 contributes only half a person to a statutory overcrowding calculation. It does not mean you cannot have a smaller bedroom in your own house.

What the Building Regulations do control in a bedroom

Not area. Three other things, and they are the ones that actually stop projects.

Escape

Approved Document B, Volume 1, paragraph 2.10 requires an emergency escape window from the relevant habitable rooms, with an unobstructed openable area of at least 0.33m2, at least 450mm high and at least 450mm wide, and the bottom of that openable area no more than 1100mm above the floor. The window must be able to stay open without being held. This is the number that decides whether a rooflight in a loft bedroom works, and it is checked on site.

Inner rooms

Dividing one bedroom into two is the classic way to create a room you can only reach through another room. An inner room with no independent escape route is a fire safety problem, not a floor area problem, and it is the reason many "we will just put a stud wall in" schemes fail at building control.

The stair

A new bedroom on a new floor needs a compliant stair. That is Approved Document K, and it sets a 220mm maximum rise, a 42 degree maximum pitch and 2m of headroom, with a specific relaxation for loft conversions. Our guide to staircase building regulations sets out the figures and the trap in the rise and going table.

The sizes that actually work

Regulations set floors, not good design. What decides whether a bedroom is usable is the bed and the space around it.

  • Standard UK bed sizes: single 90 x 190cm, small double 120 x 190cm, double 135 x 190cm, king 150 x 200cm, super king 180 x 200cm.
  • Circulation: allow about 700mm on at least one long side of the bed for getting in and out and making it, and the same at the foot if that is the route to the door.
  • Double bed access: a double used by two people wants circulation on both sides. That is a room roughly 2.75m wide before anything else goes in, which is exactly where the space standard's 2.75m double bedroom width comes from.
  • Wardrobes: 600mm deep for hanging, plus door swing or a sliding track. A 600mm wardrobe run takes a metre out of the usable width once you can open it.
  • Doors: a bedroom door swinging into the room needs its arc kept clear. In a tight room, hanging it the other way or using a pocket door is the cheapest square metre you will ever buy.

A workable single bedroom in a London house is usually around 7 to 8m2 with a 2.1m to 2.2m minimum width. A workable double, with wardrobes and access both sides, wants 11m2 or more. Those are the same order as the space standard figures, which is not a coincidence: the standard was written from furnished layouts.

Can you call a small room a bedroom?

There is no legal definition of a bedroom for the purposes of selling or letting a home in England, and no minimum size a room must reach to be described as one on a floorplan. What exists is the risk of misdescription: a room too small to hold a bed with any access is not honestly a bedroom, whatever the particulars say. If you are converting to add a bedroom for resale value, the test worth applying is whether a standard single bed and a wardrobe fit with the door open. If they do not, you have added a study.

Frequently asked questions

What is the minimum bedroom size in the UK?

For a bedroom in your own home there is no minimum, because the Building Regulations do not set one. The figures people quote come from elsewhere: 6.51m2 for one adult in a licensed HMO under the 2018 mandatory licence conditions, 7.5m2 for a single bedroom under the nationally described space standard, which applies to new dwellings only where the local plan adopts it, and 70 square feet from the overcrowding test in the Housing Act 1985, which counts people rather than setting a room size.

Is 6ft by 8ft a legal bedroom?

Six feet by eight feet is about 4.46m2. In a licensed HMO that is below 4.64m2, so it must not be used as sleeping accommodation at all and the licence holder has to notify the council of it. In a family home there is no rule preventing it being used as a bedroom, though it is below the 7.5m2 the space standard would require in a new dwelling and it will not take a bed with usable access on any side.

Does a bedroom need a window by law?

It needs one if it is a room from which people must be able to escape in a fire. Approved Document B requires an emergency escape window with an unobstructed openable area of at least 0.33m2, a minimum height and width of 450mm each, and the bottom of that opening no more than 1100mm above the floor. It also has to stay open without being held. Ventilation requirements sit separately in Approved Document F.

Does loft headroom count towards bedroom floor area?

It depends which rulebook applies. Under the HMO licence conditions, any part of a room where the ceiling is lower than 1.5m is excluded from the floor area. Under the nationally described space standard, any area with headroom under 1.5m is excluded from the gross internal area unless it is used solely for storage, and storage space with 900mm to 1500mm of headroom counts at half. Both mean an attic room measures smaller than the tape suggests.

Is the nationally described space standard mandatory?

No. It sits in the planning system, not the Building Regulations, and it applies only where a local authority has adopted it in its Local Plan and only to new dwellings. Ask the planning officer at pre-application stage. If it has been adopted, the bedroom widths, not the floor areas, are usually what forces a plan to change.

Can I split a bedroom into two?

Often, but the constraint is fire escape rather than size. Splitting a room usually creates an inner room reached only through another room, which fails on escape, and it can leave one half without a compliant escape window. Check the escape route and the window opening before you think about the partition, and speak to building control early rather than after the studwork.

Sources

Checked on 31 August 2026 against the sources above. These figures apply in England. Wales, Scotland and Northern Ireland use different documents and some different numbers. Confirm what your project is subject to with your local planning authority and building control body before you finalise a layout.