Stairs by floor height · 3.15 m · U-shaped, winders

U-shaped stairs with winders for a 3.15 m floor height

18 risers of 17.5 cm and 17 treads 28 cm deep, at 32°. 1.00 m wide, it takes 2.10 m × 2.68 m of floor. Six winders carry it round the half turn, each taking a riser, so it needs no landing.

Open this stair in uCAD What it’s made of

18risers

17.5 cmeach riser

28 cmgoing (tread depth)

17treads (the last riser is up to the floor)

32°pitch

2.10 m × 2.68 mfootprint, over the treads

The plan: steps numbered from the bottom, the walking line in blue.

More or fewer steps

3.15 m (315 cm) can be climbed in fewer, higher steps or more, lower ones. Each opens in uCAD as this stair with that many risers.

Risers	Each riser	Going	Pitch	Run of a straight flight	How it walks	In uCAD
16	19.7 cm	25 cm	38°	3.75 m	steeper, fewer steps	open
17	18.5 cm	26 cm	35°	4.16 m	steeper, fewer steps	open
18	17.5 cm	28 cm	32°	4.76 m	comfortable (drawn here)	open
19	16.6 cm	30 cm	29°	5.40 m	comfortable	open

Limits differ by country: England’s Approved Document K allows a rise up to 220 mm and a pitch up to 42° in a home, Germany’s DIN 18065 up to 200 mm, and both ask for 2.0 m of headroom. Check the code that applies to yours.

What it’s made of

Drawn as it’s built, in timber with open treads: treads housed in the stringers, posts under the turns, a railing on its newels. 250 parts in all, every bolt and weld among them. Sizes in millimetres, length × width × thickness.

Part	Qty	Length	Width	Thickness
stringer (shaped)	1	3183	429	50
stringer (shaped)	1	2822	426	50
stringer (shaped)	1	2217	351	50
tread (shaped)	1	1204	595	40
tread (shaped)	1	1357	526	40
tread (shaped)	1	1190	599	40
tread (shaped)	1	1213	587	40
tread (shaped)	1	1199	591	40
tread (shaped)	1	1356	514	40
stringer (shaped)	1	1981	264	50
stringer (shaped)	1	1638	264	50
tread	11	1030	305	40
post, timber 90x90	1	3090	90	90
post, timber 90x90	1	2002	90	90
post, timber 90x90	1	1956	90	90
post, timber 90x90	1	1582	90	90
post, timber 90x90	1	1372	90	90
post, timber 90x90	1	1190	90	90
handrail, round 50 mm (shaped)	1	1863	49	49
handrail, round 50 mm (shaped)	1	1533	49	49
baluster, steel square bar 18 mm (shaped)	17	847	18	18
baluster, steel square bar 18 mm (shaped)	4	846	18	18

Fixings: 21 × stud M8x80, glued, 21 × screw 5x45, 5 × bracket, concealed post base 90, 12 × anchor bolt M10x100, 54 × washer M10, 38 × nut M10, 10 × stud M10x117, 2 × anchor bolt M10x200, 2 × bracket, steel angle 100x100x8, 2 × stud M10x85, 16 × bolt M10x170, 16 × nut M10, barrel.

Closed risers, a steel frame, another width or railing: change it in uCAD, and the parts are worked out again, with a cut list of the boards to buy. Sizes of the structure are the library’s defaults for a house stair, not an engineer’s calculation for yours.

Another height or width

U-shaped stairs with winders for 3.15 m in 3D, between its floor and the floor above — This stair in 3D, between its floor and the floor above.

Will it fit your room?

Open it in uCAD, draw your walls round it and look: turn it the other way, move the turn up or down, change the width. Or tell the AI: “a stair for 3.15 m in a 2 × 3 m stairwell”, and it draws one that fits.

Open this stair in uCAD

Same height: Straight · L-shaped, landing · L-shaped, winders · U-shaped, landing · Spiral · Square spiral
This stair for 3.10 m · 3.20 m · all heights