Two orientations, two different walls
Orienting the sofa along the 400 cm width uses the long wall for seating, while the 300 cm depth carries the table and the walking line. Orienting it along the 300 cm depth puts the 200 cm sofa against the shorter wall and leaves 50 cm of side space on each side when centred. The same furniture reads differently in each arrangement, so run both and compare the depth total before deciding.
| Orientation | Sofa wall | Side space each side (cm) | Space on each side of table (cm) | Depth line used (cm) | Depth left (cm) |
|---|---|---|---|---|---|
| Along width | 400 cm wall | 100 | 130 | 270 | 30 |
| Along depth | 300 cm wall | 50 | 80 | 270 | 130 |
Doors, radiators, and the rectangle's blind spot
A rectangular plan records wall-to-wall distance and nothing else. An inward-swinging door claims floor area as it opens, and a radiator limits how close a sofa back may sit. Chimney breasts, boxed pipes, and window bays shrink the usable rectangle without changing the headline measurement. Walk the room with a notepad, mark each fixed feature on your sketch, and note which orientation keeps the door sweep and radiator face clear of the furniture line.
- Mark the door hinge side and the arc it sweeps when fully open.
- Note every radiator, its width, and how far it projects from the wall.
- Record window bays, boxed pipework, and any step or sill at floor level.
- Compare each marked feature against both orientations on your grid.
Footprint fit versus whole-room usability
The fit result answers a narrow question: does the entered rectangle fit the entered rectangle? It says nothing about legroom, head clearance, or whether the path stays open when people are seated. Use it to eliminate impossible arrangements quickly, then test the survivors against the doors, radiators, and routes you noted. A plan that passes the footprint check but blocks a doorway still fails in practice.
Why does the side space change between orientations?
The sofa width is compared against whichever wall it sits on. A 200 cm sofa centred on a 400 cm wall leaves 100 cm each side; centred on a 300 cm wall it leaves 50 cm each side.
Does a passing fit result mean the layout works?
No. It describes rectangular footprint fit only. Door swing, radiators, and everyday movement need separate checks you make on the room itself.
Are the example numbers standards?
No. The room, sofa, gap, and path figures shown are fictional inputs chosen to demonstrate the calculation, not recommended values.