We just found the "problem".

The "problem" is because the Stairs tool need to add 0.1mm in the corners. Why?? Maybe it's for a need in programation, but this shouldn't be a excuse to add an imprecise dimension on the stairs tool.

We work in milimeters, and this little dimension do our work less precise in industrial projects.

When will we have precise stairs?

Thanks and best Regards,
Xavier C.A.

Thanks Jorgos for your answer!

Mmmm..... Jorgos, could you attach a ndw file with your stair? thanks!

Try to change the "dimension line" parameters, using mm as a "dimension text unit" (see the attached image), or check the steps dimensions using the tool "measure length". Sure There will be any bad surprise.....

Thanks a lot!
Xavier C.A.

While we are waiting for the ndw file from Jorgos (thanks a lot!), we were testing the u-type Stairs.

In our tests, there are only one configuration of the u-type stairs, that it can heve real "zero" distance in some of the interior corners, but only in the star of landing. It's impossible to create real "zero" dimension al "end of landing". See the image attached.

The trick is to add "-0.1" as a value in the "offset at start of landing" in the "landing at bottom" and in the "landing at top".

The problem is that is impossible to create a "real zero" value at end of landing. When we try to add "-0.1" as a value in the "offset at end of landing" in the "landing at bottom" and in the "landing at top".top", the stairs tool give an error and it doesn't create the stair.

See the image "Stair 2D - test 01", to understand the stairs we want to do.

We also attach the ndw file with several tests.

Thanks!
Xavier C.A.

Hi Jorgos and thanks to post the ndw file!

We revised the stairs from your ndw file, and this stairs has the same problem. Stairs tools have a precision problem. Any CAD or BIM software has the advantage of working with absolute precision, and we are very surprised about these inaccuracies.

We change the parameters of the "dimension lines" to show the precision problem. See the attached image.

Thanks!
Xavier C.A.

Hi Jorgos! :-)

Well, we draw the "dimension lines" with maximum precision to demonstrate that the tool stairs create incorrect and imprecise geometry. Imagine that those stairs don't have drawed the "dimensions lines", and then you want to check the depth of the steps with the "measure length" tool (Messen strecke): suprise, the steps measure 0.29995. Intolerable.

By the end, this incorrect geometry will generate incorrect geometries to other elements near to this stairs, like walls, slabs, pillars, rooms, etc..

Everyone can work as everyone believe In our case, Allplan allows us to work with absolute precision. And for our misfortune, the stairs tool isn't at all accurate. It's a fact.

Best regards, Jorgos!
Xavier C.A.