topic Re: "pyramid" type stair in Modeling

"pyramid" type stair

Dave Brach — Fri, 04 Sep 2026 01:17:15 GMT

How would you model a this kind of stair? Specifically, I can edit the main stair, but I can't seem to edit the two little triangular shaped stairs on the sides. Archicad will not let me edit a stair past it's centerline so there is no way to form a triangle in plan. Or is there?

Operating system used: Mac Apple Silicon

Re: "pyramid" type stair

AllanP — Thu, 03 Sep 2026 21:55:42 GMT

I would have a single stair and wrap it around the corners.

I would draw two lines at 45 degrees from the corners.

I would then edit the stair

I would edit each tread to the new shape

remember edit treads like editing a slab/fills.

remember to set the new edges to be correct, front edges

then edit the risers

remember to edit risers like editing walls/lines

and finished you have

I don't know if this helps.

Re: "pyramid" type stair

Laszlo Nagy — Fri, 04 Sep 2026 01:20:28 GMT

@AllanP,

Can you show us how the Stair Structure looks like with this method? (I am assuming it is a Monolith.)

You could temporarily turn off the Treads and Risers so it is visible.

Re: "pyramid" type stair

Lingwisyer — Fri, 04 Sep 2026 01:39:19 GMT

I have done this several times, but the issue with it is that the actual structure does not adapt to modified treads (edit mode). It only adapts to changes in the stair boundary, the pair of green lines that appear when you click on the edges, so you cannot cut a section through it as the structure is incomplete, and you have to have a Riser finish else you just see straight into the void...

Regarding making a triangle and the centre line, you could shift the boundary of BOTH sides so that the centre line becomes one of your sides.

You get a seperate issue with modifying the Stair Boundary though as OTB someone decided that the position of the tread numbering should be a percentage of the tread width rather than a fixed amount...

Ling.

Re: "pyramid" type stair

Dave Brach — Fri, 04 Sep 2026 14:28:26 GMT

thank you for all the replies, really amazing information