A hinged door needs two different pieces of floor. On the side it opens into, the swing zone: a square of clear floor as deep as the door is wide, because that is the radius the leaf sweeps — a 900 mm door claims 900 mm. On the other side, the walk-up: about 800 mm of depth so you can stand at the door, open it and step through. Neither is optional, and the second is the one people forget.
The zones
| Zone | Depth | Applies to |
|---|---|---|
| Swing | The door’s own width (900 mm for a 900 mm door) | The side the leaf opens into |
| Walk-up | 800 mm | The other side — and both sides of a sliding or cased opening |
| Clear passage through the doorway | 600 mm minimum | Measured across the opening itself |
A double door sweeps half the total width on each leaf, so a 1600 mm double needs 800 mm of depth, not 1600.
Sliding, pocket and bypass doors have no swing zone at all — that is the whole reason to use one in a tight room. They still want the 800 mm walk-up on both sides.
Why 800 mm on the walk-up
Because you do not walk through a doorway so much as stop at it. You stand, you pull the handle, you step back around the leaf, then you go. 800 mm is the depth that fits standing plus the step back. Less than that and a door into a corridor means backing into the opposite wall every time.
The 600 mm figure is different: it is the narrowest gap the path through the door can pinch to. A chair clipping the corner of the walk-up strip while a comfortable path remains is ordinary furnishing; a sideboard leaving 400 mm to squeeze past is not.
Rules of thumb the zones are built on
- A door swings into the room, not into the corridor. A leaf opening into circulation is a hazard and eats the corridor’s width.
- Hinge on the side nearest the corner, so the leaf opens back against a wall rather than into the middle of the room, and you see the whole room as you enter rather than the back of the door.
- A bathroom door should not swing onto the toilet. Either hinge it the other way or use a sliding door.
- Two doors must not share a swing. Two leaves meeting mid-air is a mechanical impossibility, and it usually means a corridor is too short.
- A door needs wall to be hung on. Leave at least the frame post plus its architrave beside the opening — see standard door sizes.
Gridsnap checks this automatically
Four Pro rules, in the plan check (the ✓ Check / ⚠ N button at the top right):
blocks-door— swing. Anything standing in the quarter-circle the leaf sweeps: “wardrobe blocks the door’s swing”. A wall inside the swing square gets its own message — “the door can’t open fully — its swing hits a wall” — which is what you see when a door is wider than the space it opens into.blocks-door— walk-up. Furniture that pinches the 800 mm strip below 600 mm of clear span: “stairs leave under 600 mm clear to walk through the door”. Only the genuine pinch is reported, not every item that touches the strip.door-conflict. Two swinging doors whose zones overlap: “two doors swing into the same space”.no-route. No walkable route reaches a door from anywhere: “no comfortable walking route reaches this door”. When no door is reachable at all you get one finding instead of a dozen — “no entrance reaches this plan from outside” — because the cause is almost always a missing exterior door.
Something mounted above 2000 mm — a heat pump’s indoor unit over a door — is exempt from all of them. It blocks neither the leaf nor the person walking under it.
What this doesn’t do
- The swing side is not chosen for you. Gridsnap draws the swing you set (Flip swing and Flip hinge in the properties panel) and never suggests a better one; the rules only object once the leaf actually hits something.
- Escape routes are not modelled. Which way a door must open for means of escape, and how wide, is a code question Gridsnap does not answer.
- No door-to-door approach clearance. The latch-side approach space accessibility standards require is not checked.