In "Free floor space is the wrong number to look at" I wrote that I look at the narrowest gap before the square meters. At the time that was just an opinion. Now the planner reports whether each piece can be reached and how narrow the walking path gets, so I can compare with numbers.
A queen bed, a desk and a wardrobe go into a 300 × 350 cm room four different ways. A and B are the original and the fixed layout from "Will a queen bed and a desk fit in a 3 × 3.5 m bedroom?"; C and D are new. The floor covered is 4.125 m² in all four.
Only A is blocked. The bed and desk are 17 cm apart, so you can't get to the desk, and there's no way to the far end of the room either. B, C and D all work.
Ranking them by the narrowest gap gives odd results. D's narrowest gap is 15 cm, tighter than anything in A, yet D has a path that never gets narrower than 80 cm. That gap is in a corner by the wall, next to the bed, where nobody walks. C has a 25 cm gap too, and its path narrows only to 70 cm.
So I'd adjust what I said in that essay: look at the narrowest gap, but also at whether it's on a path you use every day. That's the reason the planner now shows gaps between pieces and walkable width as two separate figures.
The planner's default destination is the far side of the room, but where you actually go every day varies. Switching the destination to the desk or the wardrobe in panel 05 gets closer to your own routine. Pulling out a chair and sitting down isn't simulated.
Data
| Layout | Description | Floor covered | Narrowest gap between pieces (cm) | Gaps under 60 cm | Old | New: to far side | Narrowest point on the path | New: to desk | Out of reach | Result |
|---|---|---|---|---|---|---|---|---|---|---|
| A | Bed and desk side by side on the top wall | 4.125 m² | 17 | 2 | Not found | Blocked | – | Blocked | Desk | PASS |
| B | Bed in the corner, desk turned on the right wall | 4.125 m² | 100 | 0 | Connected | Connected | 80 | Connected | – | PASS |
| C | Bed centred on the top wall | 4.125 m² | 25 | 1 | Connected | Connected | 70 | Connected | – | PASS |
| D | Bed lowered to the middle of the left wall | 4.125 m² | 15 | 1 | Connected | Connected | 80 | Connected | – | PASS |
Where the right answers came from. A separate Python program, not the planner's code, recounted the floor area in 1 cm cells, checked the routes by joining up 1 cm points from the door, and recomputed the gaps with the distance formula for two rectangles.
Open in the planner
- Bed and desk side by side on the top wall
- Bed in the corner, desk turned on the right wall
- Bed centred on the top wall
- Bed lowered to the middle of the left wall
Running these three lines in the site's repository rebuilds the files. If the calculation code changes and these files aren't rebuilt, the site won't build, so the numbers on this page can't drift away from what the planner does.
node tools/run_experiments.mjs
python tools/verify_experiments.py