Turn an attic into a bedroom under the slope
Vault the room with the eave at the floor, drop a skylight on the slope, put the bed under the ridge, and move tall pieces toward the peak — Flow Check tells you when a wardrobe won't fit under the low side.
An attic bedroom lives or dies by the slope. The floor area looks generous; the standing-height strip under the ridge is much smaller. A dresser that fits a normal bedroom hits the roof here. Plan the slope first, then the furniture — not the other way around.
In RoomSketch3D you draw a vaulted ceiling, drop the Eave to 0 so the roof meets the floor, place a skylight on the slope, put the bed under the ridge, and let Smart Flow Check flag anything too tall for the low side ("won't fit under the sloped ceiling").
What you'll need
- •A rectangular room (16×20 ft is a good attic)
- •About six minutes
Step by step
- 1
Draw the attic and vault it
Start with a rectangle: on Home, Rectangular Floor Plan, 20 by 16 ft is a typical attic bay. In the Build Panel tap Vaulted Ceiling, then drag a rectangle over the room. Roughly is fine. Its panel opens at the bottom with the type on Cathedral (two slopes meeting at a ridge), and the plan shows the ridge as a dashed line with arrows pointing down each slope. The ridge runs along the longer side, so the two short walls are the gables (full height) and the two long walls are the eaves (where the roof comes down).
Drag a vault over the whole bay. Cathedral is the default: two slopes to a ridge. - 2
Fit to walls, then drop the eave to the floor
Tap Fit to walls (bottom of the panel) so the vault's edges land exactly on the walls. Then tap Eave, type 0 in the feet box and press Enter: it reads 0". The low side of the roof now meets the floor, with no knee wall, just the slope. Set Ridge to a real attic peak: we used 10' (120″); 9–10 ft is a common range for an attic you can stand up in down the middle.
Eave 0″ and Ridge 10′: the roof meets the floor on both long walls. - 3
Put a skylight on the slope
Tap Skylight in the Build Panel, then tap the slope where you want it. The opening sits on the vault, not on a flat plane. It starts 3′ × 4′ (36″ × 48″) with Clear glass, and its panel offers Tinted and Frosted too; frosted suits one over a future bathroom. See add a skylight for size, rotation, and glass.
Tap the slope. The skylight follows the roof, not a phantom flat ceiling. - 4
Put the bed under the ridge
Search Queen Bed, tap it and +Add. In its panel type 270 in Rotate (or tap the 90° button until the headboard faces a gable wall), then drag the bed until it sits on the dashed ridge line with the headboard against the gable. Now you sit up under the peak, not under the eave. The strip under the ridge is the only place a bed works; nightstands can sit a little down-slope, a tall headboard cannot.
Bed on the ridge, headboard on the gable. That's the strip where you can sit up in bed. - 5
Let Flow Check catch the tall piece
Search Large Wardrobe (5′ wide, 6′ 6″ tall) and push it against a long wall, the low eave side: the mistake almost everyone makes. The Flow check button turns amber with a count; tap it and the list says Large Wardrobe won't fit under the sloped ceiling (The vaulted ceiling is lower here than the item is tall). Slide it toward the ridge, or swap it for a low dresser, or put storage along a gable wall with the closet designer, until the button reads Flow check OK again.
The eave is where headroom runs out. Flow Check says so before you buy the wardrobe. - 6
Show the ceiling in 3D and walk it
Open View in 3D and tick Ceiling (bottom right); ceilings are hidden at first so you can look down into rooms. Then tap Walk through (the footsteps button) and pick a spot in the room. Face a gable wall and you see the attic as it is: the two slopes come down to the floor on either side, and the bed sits in the tall strip between them. If a nightstand looks buried in the slope, it is; move it in 2D. On the plan, Layers → Show vaulted ceilings hides the ridge lines while you furnish.
Ceiling on, then walk. The bed is under the ridge; the low sides are for low storage.
Tips
Standing height is a strip, not the whole floor
A 16×20 attic might only have ~8–10 feet of full-stand down the middle. Put the bed, the desk, and the door in that strip. The rest is low storage, a window seat, or empty on purpose.
Stairs eat the first bay
If this attic is a second floor, place the stair so the landing is in full-height space. A stair that dumps you into the eave is a head-hit every morning. See multi floor designs and add staircase.
A skylight on the slope beats a fake dormer
You can fake a dormer with a vault Top on a pyramid, but for a cathedral attic a skylight on one slope is the honest daylight. Frosted over a future ensuite.
Common mistakes
A wardrobe on the eave wall
That's the Flow Check warning in this walkthrough. Full-height storage belongs on a gable (square) wall, or as low pieces. The slope will win.
Leaving a stub of wall under the roof
If you skip Fit to walls, the vault can stop short of the walls and Flow check says The vaulted ceiling doesn't reach the wall. Tap Fit to walls in the vault's panel.
Looking for the vault in 3D with the ceiling hidden
Tick Ceiling at the bottom right of the 3D view. The same checkbox reveals the skylight.
Frequently asked questions
Why set the eave to 0?
That's the attic condition: the roof replaces the knee wall and meets the floor. A higher eave is a normal vaulted bedroom with vertical walls under the slope — also valid, but not an attic.
What does Flow Check actually catch here?
A piece taller than the ceiling at that point (won't fit under the sloped ceiling), a door or window taller than the ceiling at its spot on the wall (A door or window is taller than the ceiling here), and a vault that stops short of the walls (The vaulted ceiling doesn't reach the wall). Move things toward the ridge, lower the opening, or tap Fit to walls to clear them.
Can I do this on a traced second floor?
Yes. Vaults align to a rotated or traced plan. Draw the vault over the attic floor you already have, Fit to walls, then furnish. See vaulted ceilings for rotated plans and typed angles.
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