Box Room Ideas: 3 Layouts That Fit, Drawn in cm

The box room is the smallest bedroom in a British house. Until the 1930s, box rooms in larger houses were for storing trunks and boxes. Later they became small bedrooms, children's rooms and studies. Today the same room has to be a guest room, a home office or a child's bedroom, sometimes all three.

The good news: a box room follows a few hard numbers. This page gives them, then draws three layouts to scale for a 2.4 × 3 m box room, a common size, and says what changes in smaller rooms.

How small is a box room?

There is no fixed size. Two official figures help you judge yours. For licensed HMOs (shared houses) in England, the 2018 regulations set minimum bedroom sizes. For new homes, the Nationally Described Space Standard sets a minimum single bedroom. Neither is a rule for every home, but both are useful yardsticks.

"What fits" uses a single bed drawn at 95 × 200 cm with its frame. The HMO rules count no floor where the ceiling is under 1.5 m.
Room	Area	What fits (our arithmetic)	Against the yardsticks
2 × 2.4 m	4.8 m²	A single along the long wall, and a 35 cm-deep wardrobe opposite, 70 cm away	Above the 4.64 m² HMO minimum for a child under 10
2.1 × 2.7 m	5.7 m²	A single along the long wall with 115 cm beside it, and a chest of drawers in the 70 cm at its foot	Below the 6.51 m² HMO minimum for one adult
2.4 × 3 m	7.2 m²	The three layouts below	Above the HMO adult minimum, just below the 7.5 m² new-home single
2.7 × 3 m	8.1 m²	A small double with both sides free, or a single, a wardrobe and a desk	A single bedroom by the new-home standard

Many UK box rooms sit over the stairs, with a raised box in one corner where the stairs pass underneath. Measure its height and depth: a shallow wardrobe or a desk can often stand over it. It gives the stairs their headroom (2 m in new work, under Approved Document K), so ask a builder before you cut into it or build on it.

The sizes to plan with

Piece	Size	Source
Single bed	90 × 190 cm	Silentnight
Small single	75 × 190 cm	Silentnight
Small double	120 × 190 cm	Silentnight
Cot bed	70 × 140 cm	Silentnight
Wardrobe depth	58 cm, or 35 cm shallow	IKEA PAX
Hinged wardrobe door	25 or 50 cm wide	IKEA PAX
Desk and chair, chest of drawers	50 × 105 cm; 45 × 75 cm	Approved Document M, Appendix D
Walkway	75–90 cm; 45–60 cm in a tight room	Emily Henderson
Beside a single, new accessible homes	750 mm on one side	Approved Document M, 2.25d
In front of a wardrobe	About 90 cm hinged; 60 cm sliding	Simba

Beds are bigger than their mattresses. A frame adds a few centimetres, and a headboard more, so we draw a single at 95 × 200 cm. Check the outside size on the listing.

Layout A: a home office with a guest bed

The desk takes the window wall. A day bed along the right wall is a sofa by day and a guest bed by night.

Put the desk under the window, where the daylight falls across it. A 120 × 60 cm desk fits between the left wall and the bed. Along the right wall, a day bed that takes a single mattress (90 × 190 cm) is a sofa when you work and a bed when someone stays.

Shallow shelves, 30 cm deep, go on the left wall beside the door. That leaves a clear strip 115 cm wide from the door to the desk, wide enough to pull the chair back and still walk past it.

Want a sofa bed instead? Check two numbers on the listing: its length when open, and its size in the box. Then measure the door. Our sofa fit calculator checks whether it will go through.

Layout B: a guest room with a small double

The small double sits in the corner, against two walls. A chest of drawers and a folding stand for a suitcase take the rest.

A small double, 120 × 190 cm, is wide enough for two short stays and leaves real floor. Push it into the corner farthest from the door, with its head against the end wall and one long side against the other. That leaves 70 cm beside it, even with a chest of drawers on the opposite wall, and 100 cm at its foot.

A bedside table on the open side, a folding stand at the foot for a suitcase, and hooks on the back of the door do the work of a wardrobe for a weekend guest. The door swings clear of everything.

Why not centre the bed? In a room 2.4 m wide, a centred small double leaves about 57 cm on each side. Designers accept 45–60 cm only for a path few people use. In the corner, the guest gets one easy side instead of two awkward ones.

Layout C: a child's room

The bed's long side goes against the wall. The floor between bed and window stays open for play.

For a child, floor space is the point. A single bed along the right wall, a 100 cm wardrobe in the far corner and a low chest of drawers on the door wall leave an open play floor 145 cm wide. A 120 × 170 cm rug marks it out and stops short of the door's swing.

The wardrobe's 50 cm doors open over the play floor, not into the bed. For a younger child, a cot bed (70 × 140 cm) fits where the single goes, with room to spare at its foot. When the child needs a desk, it goes under the window in place of the rug.

Thinking of a mid sleeper or a high sleeper? It puts a desk or storage under the bed and frees the whole floor. Check the maker's minimum ceiling height, and remember a box room over the stairs may have a lower corner.

Box room ideas that win back floor

Sliding or shallow wardrobes. A hinged door sweeps its own width, 50 cm on an IKEA PAX door. Sliding doors need no swing, and a 35 cm-deep PAX saves another 23 cm.
Storage over the stair box. The raised box over the stairs is often wasted. A wardrobe or shelves built over it use space nothing else can.
Under-bed drawers. They replace a chest of drawers (about 45 × 75 cm) and give that floor back. Leave room beside the bed to pull them out.
Wall-hung shelves and a fold-down desk. Anything off the floor keeps the walkway clear.
The door. Hooks on its back hold a dressing gown and a bag. If you own, rehanging the door to open against the nearest wall can free a corner. Renting? Our guide to decorating a rented flat lists the changes that need no landlord's permission.
A rug sized to the floor, not the room. In a box room, it marks the open floor and stops short of the door. The rug size calculator lists the UK stock sizes.

Five box room mistakes

A centred bed. In a narrow room it leaves two gaps too small to use. Put a long side against the wall.
Hinged doors with no room to open. If the gap in front of the wardrobe is under about 90 cm, use sliding doors.
A desk with no room for the chair. A desk needs space behind it to sit, not just its own 50 cm of depth.
Furniture in the door's swing. A door that opens halfway makes a small room feel smaller still.
Forgetting the way in. The most common internal door in England and Wales is 762 mm wide (Howarth Timber), and the stairs up to a box room may turn. Measure the route before you order a bed frame or a sofa bed.

Planning a bigger bedroom too? Our small bedroom layout guide gives UK bed sizes, every clearance and plans for 3 × 3, 3 × 3.5 and 3 × 4 m rooms. If you want the bed placed by the feng shui tradition, the feng shui bedroom layout guide shows how it fits a box room.

See your box room before you buy

In a box room, every 5 cm counts. Snuug, the iPhone room app, rebuilds your own room in 3D from one walk round it with your iPhone, to within about 3% of its real size in our tests of ten homes. Try the day bed on each wall, open the wardrobe doors and watch the walkway, paint the wall before you buy a tin, and paste a shop link to see that desk in your room. Our team checks every room by hand before it reaches you, and your first room is free.

Questions

What can you fit in a box room?

In a typical 2.4 × 3 m box room: a single bed along one wall plus a 100 cm wardrobe and a chest of drawers, or a single day bed plus a 120 cm desk, or a small double in a corner with a chest of drawers. Put the bed against a wall and every layout keeps a clear strip of 70–145 cm.

Can a double bed fit in a box room?

Often, yes. A UK double is 135 × 190 cm, about 140 × 200 cm with a frame. Against one wall of a 2.4 m wide room it leaves 100 cm beside it, and in a 3 m long room 100 cm at its foot. It leaves room for little else, and one sleeper climbs over the other, so a small double (120 × 190 cm) is often the better choice.

What is the minimum size for a bedroom in the UK?

Two figures are quoted most. For licensed HMOs in England, a room must be at least 6.51 m² for one person over 10 and 4.64 m² for a child under 10, and a room under 4.64 m² must not be used for sleeping (2018 regulations). For new homes, the Nationally Described Space Standard says a single bedroom is at least 7.5 m² and 2.15 m wide.

What is a box room?

The smallest bedroom in a British house. Until the 1930s, box rooms in larger houses were for storing trunks and boxes. Later they became small single bedrooms, children's rooms and studies. Many sit over the stairs, with a raised box in one corner.

How do you lay out a box room?

Put the bed's long side against a wall, keep the door's swing clear, and give the storage the walls the bed does not need. Sliding or shallow wardrobes save the 50 cm a hinged door sweeps. Then check the strip of floor that is left: 60 cm is the least to walk, and 75 cm is comfortable.

Editorial notes

Written by the Snuug team and checked on 1 November 2026. A number with no source beside it is a designers' rule of thumb, not a study.