A room has to clear two numbers, not one: a floor area and a minimum clear width. A long thin room can hit its area target and still be unusable. The figures Gridsnap checks are a bedroom at 7 m² and 2.0 m wide, a living room at 10 m² and 2.4 m, a kitchen at 4.5 m² and 1.7 m, a bathroom at 2.0 m² and 1.2 m, a separate WC at 1.0 m² and 0.85 m, and a hall or corridor at 0.9 m wide with no area minimum.
The numbers
| Room | Minimum area | Minimum clear width |
|---|---|---|
| Bedroom | 7 m² | 2000 mm |
| Living room | 10 m² | 2400 mm |
| Kitchen | 4.5 m² | 1700 mm |
| Bathroom | 2.0 m² | 1200 mm |
| Separate WC | 1.0 m² | 850 mm |
| Hall / corridor | — | 900 mm |
These are advisory habitability rules of thumb, not one country’s building code. They sit at the tight end on purpose: a plan that fails one of them fails it everywhere, and a plan that passes still has to be checked against whatever your local authority actually requires.
Why the width matters as much as the area
Width is what decides whether the furniture the room is for will stand in it with room to use it.
- 2.0 m in a bedroom is a 1600 mm double bed plus 400 mm to get in on one side — the absolute floor. Comfortable is a bed with 400 mm on both long sides, so about 2.4 m.
- 2.4 m in a living room is a 900 mm deep sofa, a 600 mm coffee table, and a walking route past them.
- 1.7 m in a kitchen is a 600 mm run of units and just over a metre of aisle — see galley kitchen aisle widths.
- 1.2 m in a bathroom is a 700 mm toilet or a 900 mm shower tray with standing room in front of it.
- 0.9 m in a hall is the standard corridor minimum. Below that two people cannot pass and furniture cannot be carried through.
How Gridsnap measures it
Both numbers come off the area polygon, so what is measured is the net internal room, inside the wall faces — not the structural grid.
- Area is the polygon’s own area, the same number the properties panel shows at the top of the Area section.
- Width is the narrowest the room gets, measured across every direction its edges run in. For a rectangular room that is exactly the short dimension; for a room with an angled wall it is the tightest waist, which is the number you actually have to live with.
- Anything under 0.3 m² is treated as a drafting sliver and skipped.
Gridsnap checks this automatically — once the room has a name
The rule is room-size, part of the Pro plan check (the ✓ Check /
⚠ N button at the top right of the editor). It reports one finding per
room, naming both problems at once: “‘Bedroom 1’ is 6.4 m² — under the ~7 m²
minimum for a bedroom and is 1.85 m wide — under the ~2.0 m minimum for a
bedroom.”
The check reads the room’s name to know which minimum applies. Rooms that
Gridsnap detects on its own are called Room 1, Room 2, and those names match
nothing — so the rule stays silent until you rename them. Select the area, and
in the properties panel type into Name: Bedroom, Living, Kitchen,
Bathroom, WC, Hall. English and Estonian names are both recognised, as are
lounge, sitting, nursery, guest, shower, washroom, toilet,
corridor, entry, landing and lobby.
A combined name takes the stricter room’s minimum: an area called
Kitchen-living is checked as a living room, at 10 m².
What this doesn’t do
- It does not distinguish a single bedroom from a double. One 7 m² figure covers both. Space standards that make the distinction ask for roughly 7.5 m² for a single and 11.5 m² for a double bedroom, and the wider figure is the one to design to if the room takes a double bed.
- It is not a code compliance check. Minimum room sizes are set nationally and sometimes locally. Gridsnap will not tell you whether a plan is permittable.
- It only fires on named rooms. An unnamed room, or one called something Gridsnap does not recognise, is never checked for size, daylight or windows.
- The width test is exact for a rectangular room, generous for an L-shaped one. In a non-convex room it measures the overall extent rather than the narrow leg, so a 3 m × 4 m L with a 1.6 m arm reads as 3 m wide. Draw a dimension across the narrow part if that is the part in question.
- Ceiling height is not part of it. Many habitability rules count only the floor area under a minimum head height; Gridsnap’s rule reads the plan polygon, so a room under a low roof slope measures the same as a flat-ceilinged one.