STAIR PLAN GRAPHICS: Hide Bottom Tread when set to 'Start with Tread'?

[Jeff Galbraith]

We are 2 years into our transition to Archicad and still grappling with how best to use the stair and railing tools. We are running into a plan graphic issue when associating handrails to stairs. The associativity provides the benefit of having the handrails crop at the same line as the stairs they follow, but it is causing us issues with handrail generation at the bottom of the stairs.

Our standard approach so far has been to set stairs to 'Start with Riser' rather than 'Start with Tread'. We choose this options because if we choose 'Start with Tread' it creates the false appearance in plan that there is an additional tread (and associated riser) at the bottom of the stairs, coplanar with the landing surface. The 3d model does not show this mythical tread at the bottom story, it is only visible in the plan symbol. However, when associating a handrail to the stair the handrail does not extend far enough down at the bottom end...it stops at the first nosing above the landing which is not code compliant. If we modify the handrail settings to extend it then it extends too far at the top of the stair. The handrail tool does not appear to give us the option to differentiate extension length at the top vs the bottom.

So we are forced to either use 2D fills to hide the mythical bottom tread from view in plans, or stick with 'Start with Riser' and locally modify the bottom node of the handrail to correct the bottom extension length. Unfortunately once you modify the placement of a node it breaks the associativity of that node to the stair and makes it impossible to perform future modifications to the railing using settings. ie: if you try and modify the offset parameter for example the offset will not apply to the bottom segment of handrail related to that node...so you basically have to rebuild the handrail.

This could all be solved if it were possible to hide this mythical bottom tread shown in the plan symbol. Is this possible? Please?

[Laszlo Nagy]

Could you post a few screenshots about this Handrail extension situation at the bottom of the Stair?
From your description, it sounds to me that you should be able to specify the exact extension length for that Handrail.

[Jeff Galbraith]

The problem with the extension parameter is that it gets applied to both the top and bottom of the handrail equally...and the tool doesn't allow you to have a different extension at the top vs the bottom.

Below is a screenshot of the bottom of a stair set to "Start with Tread":
The red dot indicates the bottom of the handrail that is created when associated with the stair. This creates a correct handrail, but the plan shows the 'mythical' tread I referred to in the original post.

Below is a screenshot with the stair set to "Start with Riser":
Again the red dot is the node that determines the base of the railing...which is too high. Code requires the handrail to continue at the angle of the stairs until for one tread length past the lowest riser. In other words, this red dot needs to be where it is located when choosing 'Start with Tread'. However if I change the extension setting for the handrail end to fix it at the bottom, the software also extends it at the top, so the top is no longer code compliant because it extends too far.

[Laszlo Nagy]

Could you also show screenshots of the Handrail and both the bottom and the top of the Stair along with the parameters set in the Settings Dialog page that controls it?
For me, it is possible to control the end length of the Handrail on both sides independently.

[Jeff Galbraith]

Here's the settings for the handrail:


Here's the resulting railing. The bottom doesn't extend far enough. The red dashed line is what I need.


Here's modified settings to get the bottom to extend further:


Here's the result. You can see that the railing extend at bot the top and bottom equally.

[Barry Kelly]

Instead of applying the settings to the entire handrail, go into EDIT mode and select just the bottom end - you can do this easily in 3D.
Then you can change the end settings and it will apply only to the bottom end.


Barry.

[Jeff Galbraith]

The problem with that approach Barry is that as soon as you modify the bottom end using the edit tools you break the associativity of whatever node or segment you customized. This is OK only if EVERY other aspect of the handrail is correct and doesn't get modified later. Unfortunately this is almost never the case in practice.

For example: If you try and go back and change the offset parameter for the distance between the baseline and the handrail after you have made an 'edit' (such as to adjust the distance between eh handrail and the wall or guardrail) the changes will not apply the same to the customized node / segment as it will to the rest of the handrail, and you end up with strange, incorrect and distracting geometry that you cannot make right. You're then forced to rebuild the handrail all over again from scratch. Having staff rebuild handrails every time their drawings get reviewed and marked up with comments is not efficient business. It's expensive enough just to pay staff to learn the program to start with...

[Barry Kelly]

Jeff wrote:
The problem with that approach Barry is that as soon as you modify the bottom end using the edit tools you break the associativity of whatever node or segment you customized. This is OK only if EVERY other aspect of the handrail is correct and doesn't get modified later. Unfortunately this is almost never the case in practice.

I understand your frustration at this, but I am not sure how Graphisoft can get around it.
You want to customise a portion of your railing to be different to the overall settings but you still want your railing to conform to the overall settings.
I don't think that is possible.

That is what those little yellow warning triangles are there for.
They allow you to reset to uniform settings, but then you will need to go back and customise parts again after you make the uniform changes.


Barry.

[Lingwisyer]

It would be nice if they made only the parameter you edited non-associated whilst all of the other settings remain. Quite a few times I have just wanted a different offset for one or two segments...



Ling.

[runxel]

Lingwisyer wrote:
It would be nice if they made only the parameter you edited non-associated whilst all of the other settings remain. Quite a few times I have just wanted a different offset for one or two segments...

Exactly! This is the solution that should be obvious here.
GS chose the "easy" (fro them) approach by making the associativity node-based, instead of parameter-based.