AC21 - Double winder stairs

[Anonymous]

Goodmorning, I'm a new AC user and I don't find a solution to create a stair with a double winder (start and finish). Any suggestions? Thanks you a lot.

[fuzzytnth3]

Checkout this video scroll to about 3 minutes and he shows you how to do a winder

Youtube ArchiCAD video AC21 Stair tool

[Anonymous]

Thank you for the reply.
I've watched that video, but I'm still not able to create a stair similar to my attached image.

[Hmooslechner]

This image shows a stair, that definitely is not allowed in Austria, because it is forbidden to define the lines of the winder to one single point.

With our legalized rules, there has to be a minimum of 15 cm to step on at 20 cm from the inner border, which leads to a minimum distance of about 8-10cm for each riser.

So - from our Austrain point of view, such a stair is not possible and would be a little bit dangerous for old people and children.

If You are capable in reading german texts - point 3.23:
https://www.oib.or.at/sites/default/files/richtlinie_4_26.03.15_0.pdf

So - PLEASE DONT DO IT THIS WAY - make the stair bigger and safer!

BtW. I also think, that this form should be no problem to design in Archcad - but it isnt!

[Anonymous]

Thanks you for the answer.
I know that it's a strange and dangerous stair, but I have to model it because it's part of an existing building in the UK, but I didn't find the way to do that in ArchiCAD (with the stair tool).

[Anonymous]

This is as close as i could get.

[Anonymous]

This is actually an issue I'm facing too. Is it possible in ARCHICAD to do this? In Australia this type of winder is legal. How I have finally achieved it is editing the individual winders in the "Edit Stair" environment but it is rather fiddly.

[Laszlo Nagy]

Hi guys,

I looked at this issue to see if I can come up with a relatively simple solution and I found a way.

Check the attached image.
Notice that the Stair Baseline (thick blue line) is on the outside (right side of Stair).
Also notice that before starting to draw the Stair Baseline I selected the "Winder with Equal Angles" option for Turning Type, I selected the "Fixed Number of Going" option, with a value of 3, and I also chose the "Fixed Riser Offset" option, with 0 millimeters as value for both fields.

Then I drew the Stair Baseline in a way that at the second turn (left turn) I turned one tread earlier so now 1 tread is hanging out from the lower horizontal line of the Stair. I will later modify this to achieve the exact result.

[Laszlo Nagy]

Now I clicked the second Turning, chose the Turning Type Options command from the Pet Palette, and modified the 2nd Fixed Riser Offset value from 0 to 0.1 mm.
It looks like ARCHICAD will not construct the Stair if that value is zero, so I set it to a very small value which will not even be visible unless you zoom in very closely, plus it will not be visible in Dimension either because of rounding.

(Notice that after the change the left Dimension shows 1.5001 m. When rounding is set to mm, this will read 1.500 m.)

[Laszlo Nagy]

Now I select the left vertical segment of the Stair Baseline and use the Offset Edge command to offset the edge by the Tread Depth value (Going value - 300 mm in this case).
The horizontal section of the Stair will contain one more step, and the turn is correctly calculated by ARCHICAD since the last Riser is offset 0.1 mm.