Every uncomfortable room is a few hundred millimetres away from a good one. The bathroom you have to sidle into, the kitchen where the dishwasher door blocks the sink, the bedroom where one person climbs over the other — none of them were designed that way, they were drawn that way and nobody checked the gaps.
This is the cheat sheet: the numbers Gridsnap's own plan checker uses, and the ones worth keeping in your head while drawing. They are conventions and rules of thumb — good across most residential work, but not building code. Codes are national and sometimes municipal, so check yours before anything goes in for permission.
Minimum room sizes
A room needs an area and a width. Twelve square metres arranged as a 1.5 m corridor is not a bedroom, which is why the second column matters as much as the first: measure the room's narrowest real dimension, not its average.
| Room | Min area | Min width | Note |
|---|---|---|---|
| Bedroom (single occupancy) | 7 m² | 2.0 m | Below this a bed and a wardrobe leave no floor. |
| Living room | 10 m² | 2.4 m | A sofa is 900 mm deep; you need to walk past it. |
| Kitchen | 4.5 m² | 1.7 m | One 600 mm run plus standing space; 2.4 m for two facing runs. |
| Bathroom | 2.0 m² | 1.2 m | Enough for a WC and basin. A bath needs 1.7 m in one direction. |
| Separate WC | 1.0 m² | 0.85 m | Door swinging outward, or you cannot close it behind you. |
| Hallway / corridor | — | 0.9 m | 1.0 m if doors open into it; 1.2 m for wheelchair turning. |
These are floors, not targets. A comfortable double bedroom is 11–13 m², a family living room 18–25 m², a kitchen you can cook in with someone else 8–10 m².
Clearances: the gaps that matter
Furniture sizes are easy to look up. What people forget is the empty floor around the furniture — the space a body occupies while using it. These are the ones worth memorising:
| Clear space | Keep | Why |
|---|---|---|
| In front of a door, both sides | 800 mm | Plus the swept swing. The inside is forgotten far more often than the outside. |
| In front of a window | 600 mm | You need to reach the handle and the sill. |
| In front of a WC | 600 mm | Measured from the front of the pan to whatever is opposite. |
| WC centreline to each side | 400 mm | To a wall, the basin, or the bath edge. |
| In front of anything you open | 550 mm | Wardrobe, fridge, dishwasher, oven — room to stand and swing the door. |
| Beside a double bed | 400 mm | 700 mm if both sides are used nightly. |
| Aisle between facing kitchen runs | 1050 mm | Two people, one open appliance door. 1200 mm is comfortable. |
| Walking route through a room | 600 mm | The width a person actually needs between obstacles. |
Doors, corridors and stairs
- Internal door leaf: 800–900 mm for rooms you carry furniture into, 700–800 mm for a WC or store. Under 700 mm, a washing machine stops fitting through.
- Entrance door: 900–1000 mm.
- Door head height: 2100 mm as standard, which is also what the 3D view and elevations assume.
- Which way it swings: into the room, against the nearest wall, so the leaf parks flat and doesn't sweep the room. Small WCs are the exception — outward, or the door hits your knees.
- Corridor: 900 mm absolute minimum, 1000 mm where doors open into it, 1200 mm for wheelchair turning.
- Stairs: 900 mm clear flight width for a home; riser 170–190 mm with a going of 250–280 mm; and headroom of 2000 mm over the whole flight — which is what the stairwell opening in the floor above is for.
Kitchen
Kitchens are the room where a hundred millimetres is felt daily. Three numbers carry most of it:
- The work triangle — sink, hob, fridge. No leg longer than about 2.7 m, and no more than roughly 7.9 m in total. Too spread out and you walk all evening; too tight and two people cannot both be in it.
- A worktop landing beside the hob and beside the sink. Somewhere to put the hot pan down and somewhere for the wet dish. A hob at the end of a run with nothing next to it is the single most common kitchen drawing error.
- The aisle between facing runs: 1050 mm minimum, 1200 mm to be comfortable. Both a dishwasher door and a person are ~600 mm.
Standard depths: base units 600 mm, worktop height 900 mm, wall cabinets 350 mm at 1400–1500 mm. Keep the hob away from the window (curtains, draughts) and the fridge away from the cooker (heat). Both are checked automatically in Gridsnap.
Bathroom
- WC: 600 mm clear in front, 400 mm from the centreline to each side. That is the difference between sitting down and wedging yourself in.
- Basin: 550 mm of standing room in front; 850 mm rim height.
- Bath: 1700 × 750 mm is the standard; leave 700 mm alongside to get in and dry off.
- Shower: 900 × 900 mm is the smallest that feels like a shower rather than a cubicle. 800 × 800 works but you touch the walls.
- An 1800 × 2000 mm room fits a WC, basin and shower properly. Below about 2 m² something has to go.
Bedroom
- Bed sizes: single 900 × 2000, double 1400 × 2000, king 1600–1800 × 2000 mm.
- Access: 400 mm down at least one side, 700 mm if both sides are slept in. Bedside cabinets are 400 mm — they live inside that gap, not beside it.
- Wardrobes: 600 mm deep (a hanger is 550), plus 550–750 mm to stand and open the doors.
- Not under the window: a bed head under glazing means draughts and a window you can't open from the bed. High sills — 1200 mm and above — are fine.
Living room
- Sofa to TV: 2.4–4.0 m for a normal screen. Closer and it dominates; further and you squint.
- Sofa to coffee table: 400 mm — enough to get past, close enough to reach your cup.
- Around a dining table: 800 mm from the table edge to the wall so a chair can be pulled out and walked around. 1000 mm where people pass behind seated diners.
- Don't point the TV at the window. A screen facing glazing fights daylight all day; turn the seating group 90°.
Daylight and windows
The old rule of thumb, and still a good one: glazed area of at least one eighth of the floor area in every habitable room. A 16 m² bedroom wants ~2 m² of window — one 1.2 × 1.4 m window is not quite enough, two are comfortable.
Sill heights: 900 mm is the usual default; 1200 mm and above where you want furniture or a worktop below; down to floor level for a French window or a door. A window with a 900 mm sill has a wardrobe standing in front of it if you're not careful — that is a plan-stage decision, not a furnishing one.
Furniture dimensions
Standard sizes in millimetres, width × depth. Every one of these is a parametric item in Gridsnap that you can resize to whatever you actually own:
| Sofa (3-seat) | 2000 × 900 |
| Armchair | 850 × 850 |
| Coffee table | 1200 × 600 |
| TV bench | 1600 × 450 |
| Dining table (4–6) | 1600 × 900 |
| Dining chair | 450 × 480 |
| Desk | 1400 × 700 |
| Double bed | 1600 × 2000 |
| Single bed | 900 × 2000 |
| Bedside cabinet | 400 × 400 |
| Wardrobe | 1500 × 600 |
| Kitchen base unit | 600 × 600 |
| Fridge / freezer | 600 × 650 |
| Cooker / hob unit | 600 × 600 |
| Bathtub | 1700 × 750 |
| Shower tray | 900 × 900 |
| Basin | 550 × 450 |
| Toilet | 400 × 700 |
Checking it instead of remembering it
Nobody holds forty numbers in their head while drawing. In Gridsnap they are applied automatically: as you place walls, doors and furniture, the plan checker measures the real geometry and tells you which gap is short and by how much — 600 mm needed in front of the toilet, 430 mm drawn. Clicking a finding zooms the drawing to the spot.
Ready to draw? Start with how to draw a floor plan, or open a template that already respects all of the above and change it into your home.