Walk-in closet minimum width
A walk-in closet is a room with an aisle in it. Everything about whether the room is big enough comes down to one sum: the depth of the units on each wall, plus the aisle you leave between them. Get the aisle wrong and no amount of clever shelving rescues the layout, because you will not be able to stand in front of it.
The aisle is 900 mm
900 mm (35 7/16 in) is the working figure for the clear space between a run of units and whatever is opposite — the far wall, or a second run. It lets you stand square to a shelf, crouch to reach a bottom drawer, and pull a drawer fully out without your back hitting the wall. It is also roughly the width of a doorway, which is a useful check: if the aisle is narrower than the door you came through, it is too narrow.
You can build tighter. At 800 mm (31 1/2 in) the room still functions for one person; at 700 mm (27 9/16 in) you are turning sideways and opening drawers halfway. Treat anything under 900 mm as a deliberate compromise rather than a plan.
One wall: 1500 mm across the room
Units on one long wall only, everything else clear. 600 mm (23 5/8 in) of unit plus a 900 mm (35 7/16 in) aisle gives 1500 mm (59 1/16 in) as the smallest useful room depth. This is the layout for a narrow room, and it has a hidden advantage: the opposite wall stays free for a mirror, a window, or the door.
Two facing walls: 2100 mm between them
Two runs facing each other doubles the storage for the same length of room, and needs 600 + 900 + 600 = 2100 mm (82 11/16 in) wall to wall. This is the most efficient walk-in shape there is. Below 2100 mm (82 11/16 in), drop one run to 500 mm (19 11/16 in) deep or accept a narrower aisle — do not squeeze both.
U-shape: 2100 × 2400 mm
A U wraps three walls and is the layout most people picture. Across the two facing runs you still need 2100 mm (82 11/16 in). Along the room you need enough length for the end run plus room to stand in front of it and still get through the doorway: 2400 mm (94 1/2 in) is the practical minimum. Anything shorter and the end run becomes a corner you cannot reach into.
The door
Put the door in a short wall at one end if you can, so the long walls stay clear for units. A clear opening of 700–900 mm (27 9/16 – 35 7/16 in) is right; wider is a waste of wall. Walk-in Planner keeps a margin of 80 mm (3 1/8 in) each side of the door span, so an 800 mm (31 1/2 in) door removes 960 mm (37 13/16 in) of wall from the layout — and it splits that wall into two independent runs, which is often what pushes a design from three units to two. An inward-swinging door also sweeps an arc across the aisle; the plan drawing shows it, so you can see what it collides with before you commit.
Minimums by layout
| Layout | Units | Aisle | Minimum room size |
|---|---|---|---|
| One wall | 600 mm (23 5/8 in) | 900 mm (35 7/16 in) | 1500 mm (59 1/16 in) across |
| L-shape | 600 mm (23 5/8 in) on two adjoining walls | 900 mm (35 7/16 in) | 1500 mm (59 1/16 in) in each direction |
| Two facing walls | 2 × 600 mm (23 5/8 in) | 900 mm (35 7/16 in) | 2100 mm (82 11/16 in) between them |
| U-shape | 600 mm (23 5/8 in) on three walls | 900 mm (35 7/16 in) | 2100 × 2400 mm (82 11/16 × 94 1/2 in) |
| Doorway | — | — | 700–900 mm (27 9/16 – 35 7/16 in) clear |
Corners
Two runs meeting in a corner always cost something: the last part of one run is buried behind the other. The planner resolves this for you — the back and front walls own the corners, and a side wall only gives its corner up when the neighbouring run is long enough to be worth building. What you see on the plan is what you can actually reach.
Enter your room and door position, tick the walls you want to build against, and the planner tells you straight away whether the aisle that is left is one you can live with.