A piece of furniture has to fit three times over, and the three are independent. It has to fit along the wall it is going against. It has to fit past the narrowest opening on the route to that wall, which is a different and usually harder test because it involves turning it. And it has to leave enough room to walk past once it is there. Failing any one of the three is failing, and the door is the one people forget — a sofa that measures perfectly against the wall and will not go round the bend in the hall is a sofa that goes back in the van.
Wall, piece and route
Three separate fits: along the wall, past the door, and room to walk by.
To the top of the back, not to the seat.
The opening, not the door leaf. Take the door off if it helps.
Ninety centimetres is comfortable; sixty is a squeeze.
Result
The door is the test people forget
Measuring a piece of furniture against a wall is easy, and it is what everyone does. Measuring it against the route to that wall is what gets skipped, and it is where the failures are. The narrowest opening on the route — a front door, a hallway door, a turn at the bottom of the stairs — is a hard limit, and for a large piece it is usually harder than the wall it is going against.
Two things help before concluding that it will not go. Taking the door off its hinges gains fifty to seventy millimetres, which is often the whole difference. And turning the piece on its diagonal uses the height of the opening rather than its width: a piece 450 deep and 750 high has a diagonal of 875 millimetres, which goes through a 2 metre opening easily even if the door itself is narrow.
What counts as enough room to walk past
Ninety centimetres is comfortable for one person walking past furniture. Sixty is a squeeze that people tolerate in a hallway but resent in a living room. Below about forty-five, people turn sideways, and a route that needs sidling gets avoided — which is how a room ends up with a path worn around the outside of it.
It is worth measuring in the right place. A walkway past a sideboard in a dining room has to be clear where the chairs are pulled out, not where they are pushed in. A passage beside a bed has to be clear with the drawer open. The furniture is not the only thing occupying the space.
A door leaf is narrower than the opening it hangs in, and taking it off the hinges gains the thickness of the leaf and the gap — often sixty millimetres.
Also check the turn. A piece that fits the door may not fit the corner immediately behind it, and a stair with a turn at the bottom is the classic trap.
Depth is the dimension that bites
Width is what people measure and depth is what costs them. A sofa is usually advertised by its width, and a 2.4 metre sofa at 950 millimetres deep takes a genuinely different amount of room from a 2.4 metre sofa at 800 deep — a hundred and fifty millimetres of floor, and a hundred and fifty millimetres off the walkway in front of it.
Deep seating is comfortable and it is also what makes a room feel cramped. In a room under about four metres wide, a deep sofa against one wall and a television unit against the other leaves very little, and the honest answer is a shallower piece rather than a smaller room.
| Piece | Typical depth | In a 3.4 m room | Note |
|---|---|---|---|
| Sofa, standard | 0.90 m | 2.50 m walkway | Comfortable |
| Sofa, deep | 1.05 m | 2.35 m walkway | Very comfortable, very big |
| Sofa, compact | 0.80 m | 2.60 m walkway | For a narrow room |
| Sideboard | 0.45 m | 2.95 m walkway | Little impact |
| Bookcase | 0.30 m | 3.10 m walkway | Depth is not the issue |
| Armchair | 0.85 m | 2.55 m walkway | Depends where it sits |
A worked example
- Along the wallTwo pieces at 1.6 m, plus a 50 mm gap, use 3.25 m of a 3.6 m wall: 0.35 m left.
- Across the roomA 450 mm deep piece in a 3.4 m room leaves 2.95 m of walkway.
- Through the doorAn 800 mm opening against a 450 mm depth leaves 0.35 m of slack — it goes through square, no tilt needed.
- If it did notThe diagonal of 450 by 750 is 0.87 m, well under the 2 m height of the opening, so a tilt would work.
- VerdictAll three pass, with the wall being the tightest of them.
In this case the wall is the binding constraint and the door is not, which is the common case for a piece that is wide and shallow. Tall and deep is the combination that turns the door into the problem.
Getting it in
Measure the route before the delivery, not on the day. Walk it with a tape: the front door, the hall, any turn, the stair if there is one, and the door into the room. Note the narrowest point and the tightest turn separately, because they fail in different ways.
Wrap the piece, protect the corners, and take the doors off. Carry on the diagonal where you can, and tilt rather than force — furniture is much more likely to be damaged by being pushed at an opening than by being carried carefully around it.
Once it is in, the room is worth checking properly rather than by eye. The room area figure gives the floor to work with, the rug figure sizes what goes under the seating group, and where the storage is going on the same wall the storage volume figure works out whether it actually holds what you have.
Do
- Measure the narrowest opening on the route, not just the wall.
- Take the doors off their hinges before concluding it will not go.
- Remember the diagonal uses the height of the opening.
- Measure walkway where chairs are out and drawers are open.
- Check the tightest turn separately from the narrowest point.
Avoid
- Measuring the wall and not the route to it.
- Forgetting the corner immediately behind the door.
- Measuring the door leaf rather than the opening.
- Judging walkway with the furniture pushed in.
- Forcing a piece at an opening instead of tilting it.
Where the numbers stop being true
The wall test is one-dimensional. It assumes the pieces sit in a straight line against a flat wall with nothing on it — no skirting that stands them off, no radiator, no socket, no light switch, no chimney breast that shortens the usable length by more than it looks.
The door test is a straight push through a rectangular opening. A real move involves turning, and a turn needs more room than a push: a long piece going round a corner in a narrow corridor is a three-dimensional problem that no two-number check resolves, and the honest test is a cardboard template or a piece of string cut to length.
And nothing here accounts for assembly. A sofa with removable legs, a bed with a split base, a wardrobe that flat-packs and builds in the room — all of those turn an impossible move into a routine one, and they are worth checking before deciding that a piece cannot go in.
How the figures are produced
Wall used is the number of pieces times the width, plus the gaps between them. Space left is the wall length less that, and a negative figure means it does not fit. Walkway left is the room width less the depth of the piece. Slack through the door is the opening width less the depth, and the diagonal is the square root of depth squared plus height squared, which is what is available if the piece has to be tilted through the opening.
Questions people ask
Will my sofa fit through the door?
Check the depth against the opening width first. If that fails, the diagonal of depth and height against the opening height usually works.
How much walkway do I need?
Ninety centimetres is comfortable, sixty is a squeeze, and below forty-five people turn sideways.
Should I take the door off?
Yes, if it is close. It typically gains fifty to seventy millimetres, which is often the whole margin.
Can I turn it on its end?
Usually. The diagonal of the depth and height is what has to clear the opening, and for most furniture that is well under a door height.
Do I measure the door or the frame?
The opening — the frame — with the door removed. The leaf is narrower than the hole it hangs in.
What if it still will not go?
Check whether it comes apart. Removable legs, a split base or a flat-pack frame turn most impossible moves into easy ones.