Hello everyone,
I'm trying to model a stair where the first four treads are "compensated" (meaning the nosing is adjusted to fit a specific landing or winder condition), and from the 5th tread onwards, they are standard, equal treads, like the floor plan below.
I'm working in Archicad 28 and using the Stair Tool. I can successfully create the compensated treads and risers by dragging the nodes in the floor plan, but the problem is that the stair's underlying structure remains unchanged, which causes issues for the rest of the flight.
Is the best approach to model this as two separate stair elements? Or is there a way to define a "transition node" within a single stair object where the tread compensation stops and the structure recalculates for standard treads?
Does anyone has any experience in this?
Thanks in advance.
Hector
Operating system used: Windows
Hi @Lingwisyer , @Barry Kelly, and all,
Thank you both for your replies and for linking the video. I appreciate the help.
I believe I’ve hit a more specific constraint. The techniques shown (and in the linked video) work perfectly for designing a new stair freehand, where you can adjust the boundary lines freely until it looks right. Like this one I just made
My situation is different: I am redrawing an existing stair from precise field measurements. I have fixed dimensions for:
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Total rise and run.
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The exact geometry of the compensated treads.
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The exact point where the stair transitions from this curved start to a straight run.
When I follow the standard method—adjusting the boundary lines while keeping the stair path (blue line) curved—the structure still fails to match the tread and the rise finish.
My Question: Is there a way to force the stair's structural geometry to strictly follow user-defined node placements on the boundaries, even if it creates a more complex or less "ideal" transition? Or, when documenting an existing irregular stair with precise dimensions, is the accepted workflow to:
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Model the treads/risers with the Stair Tool for scheduling.
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Then manually model the actual, as-built structure/soffit using the Morph tool?
I’ve attached a portion of my blueprint with the key dimensions highlighted. Any guidance on the best practice for accurate documentation (not just design) would be incredibly valuable.
Thanks again for your time.
Hector
@Heftor wrote:
My situation is different: I am redrawing an existing stair from precise field measurements. I have fixed dimensions for:
Total rise and run.
The exact geometry of the compensated treads.
The exact point where the stair transitions from this curved start to a straight run.
When I follow the standard method—adjusting the boundary lines while keeping the stair path (blue line) curved—the structure still fails to match the tread and the rise finish.
Looking closer at your images, the dimension on the right side of the treads all appear to be the same ... 170mm.
If these are being generated from a curved stair structure where the treads emanate from a single centre point, this will not be possible.
As you can see in your last image.
So, this method only works if your treads emanate from a single centre point.
The equal treads in your example will all have separate center points (or pints of origin).
Rather than a circular or spiral beginning to your stair case, you can have winders with varying origin points.
Something like this, but I just don't know how to incorporate a winder into your stair.
I don't model a lot of stairs and when I do they are not usually curved.
At the moment I can only suggest modelling those angled treads from separate slabs.
Barry.
Still looking?
