Oatmeal plan diagram of a window wall showing radiator projection, sill, curtain stack, and the leftover desk rectangle.
The listing width is the wall. The desk width is what remains after heat, glass, and fabric.

Radiator and window-wall allowance

Window walls look like free width. Then a radiator, a sill, and a curtain stack take the depth you thought you had — or they block the leftover run you measured from a photo.

This is a dimension guide. Pair it with the desk size guide and window glare.

What to subtract

Tape these projections from the finished wall, not from the glass.

Object Typical projection (planning) What it steals
Panel radiator ~3.9–5.9 in (10–15 cm) Depth if the desk must sit in front; width if you keep a heat gap to the side
Window sill ~1.2–3.1 in (3–8 cm) past the plaster Depth, plus a glare path onto the screen
Curtain + rail ~3.1–4.7 in (8–12 cm) stacked Width at each end of the run; sometimes depth if the stack sits over the desk
Baseboard ~0.4–0.8 in (1–2 cm) Flush-mount folding brackets

These are typical ranges. Your building wins. If the lease wants radiators unblocked, a 60 cm desk shoved against a 12 cm heater is two failures: heat and chair zone.

Worked leftover

Wall is 240 cm. Door swing claims 80 cm. Radiator / curtain margin on the window end claims 40 cm. Nightstand overlap 20 cm. Leftover for the desk: 100 cm. That is a 100 × 50 cm top, not a 140 cm “office” desk. Same arithmetic as the size guide’s bedroom example.

If you refuse the 40 cm window margin and park the desk on the heater, usable depth drops by the radiator projection. A 50 cm top becomes ~35–40 cm of real work. Skip, or rotate to a side wall.

When the window wall is still the right wall

  • You can sit with glass beside you, not behind the camera.
  • The heater stays clear (desk beside it, not on it).
  • Rollback still meets the sit-test after the sill.

When it fails: glare you cannot kill with a sheer, a heater that forbids a rear gap, or a sill that turns the top into a plant ledge. Then the desk moves.