Leaf undercut limited to 50mm max

[Anonymous]

Leaf undercut limited to 50mm max? Is that intended behavior? can't see why it would be though.

[Minh Nguyen]

Hi Benjamin,

Thank you for your question!

This is a limitation for the Door object in ARCHICAD. It can be modified by diving into library or GDL editing, but it is not a simple process. To be honest, I'm not really sure why this limitation is set up to 50mm. We will need to bring this question to the developer in order to understand why!

May I ask you what will be the situation where you need to raise this higher than 50mm? Maybe we can look into this and increase the upper bound of the Undercut, if it is necessary!

As soon as I have an answer, I will reach out to you again. Thank you very much!

Best regards,
Minh

[Anonymous]

Thanks Minh. 100mm undercut to doors is not an uncommon design so my opinion is that there shouldn't be a limit to the undercut in the script (or at least should be limited to door leaf height so you can't undercut more than the height of the door leaf)

[Minh Nguyen]

Hi Benjamin,

Our developers have given us an explanation for this issue. From a technical point of view, this limitation could be higher, but this parameter reduces the height of the door panel, and that gives unsatisfactory results for many panel types. That's why we limit it to 50.

There are 2 ways to get around this issue, but they are not easy to do. There is already an existing wish to modify this behavior. I hope this will change in the future!

You can find the solutions below.

Solution 1: for a few objects:
- open "gs_general_lt_door_macro"
- comment out in param script the line values "gs_leaf_undercut" range [0, 0.05]
- save as "custom_general_lt_door_macro" in embedded library
- save each door as a new object with a different name in the embedded library
- rewrite in each master script call "gs_general_lt_door_macro" to call "custom_general_lt_door_macro"
- the modified doors won't be able to migrate forward to ARCHICAD Library 22

Solution 2, for many objects:
- unpack the "ARCHICAD Library 21.lcf" using File / Libraries and Objects / Extract Container
- in Library Manager change the library to the unpacked folder
- open "gs_general_lt_door_macro"
- comment out in param script the line values "gs_leaf_undercut" range [0, 0.05]
- pack the modified library using File / Libraries and Objects / Create Container to "ARCHICAD Library 23.lcf"
- any library updates will undo this change

Thank you for your understanding!

Best regards,
Minh

[Anonymous]

I cannot understand why you would have an undercut even as much as 50mm.
In 20+ years of practice I have never approved an undercut of more than 20mm and then it would require a really thorough / convincing explanation from the mechanical engineer as to why this cannot be achieved another way as acoustic performance of the door will be nonexistent and appearance poor.
If you are using undercut to accommodate for floor finish thickness you are using the wrong parameter, use subfloor thickness.

Regards
Scott

[Erwin Edel]

Scott, while I also can't see a need for such a huge gap, I'm unaware of the subfloor thickness parameter.

In our projects, typically, there is a cement floor and on top of that we have a 20 mm margin for floor finishes. Most of the doors need a 10 mm gap for ventilation. Since the frame is placed in the 'rough' phase of construction, we need a 10+20=30 mm gap.

I've been using the undercut parameter for this and it is working fine, but the subfloor thing sounds interesting. Could you share a screenshot of where you set the parameter, so I can try to look for it in our local library version?

For Benjamin: if you need a door with a huge gap, perhaps it is also possible to script a leaf which has a gap.

[Lingwisyer]

Under Dimension Marker? It sets a Sill parameter, but does not actually change anything else?

[Anonymous]

Erwin wrote:
Scott, while I also can't see a need for such a huge gap, I'm unaware of the subfloor thickness parameter.

In our projects, typically, there is a cement floor and on top of that we have a 20 mm margin for floor finishes. Most of the doors need a 10 mm gap for ventilation. Since the frame is placed in the 'rough' phase of construction, we need a 10+20=30 mm gap.

I've been using the undercut parameter for this and it is working fine, but the subfloor thing sounds interesting. Could you share a screenshot of where you set the parameter, so I can try to look for it in our local library version?

For Benjamin: if you need a door with a huge gap, perhaps it is also possible to script a leaf which has a gap.

Erwin,
my mistake, it is not a "subfloor thickness" but is "sill offset" parameter, refer attached image. You can use a property to calculate frame height as the sum of the sill offset and the door frame height. This way the door undercut will just be for air relief / seals etc. I typically only schedule leaf size and dimension to the hinge side of the door, I do not dimension the opening size as the final clear opening size is what is important to the projects I work on.

Regards,
Scott

[ChrisB]

We work on similar margins to Erwin i.e. 25/30mm gap under leaf to allow for final floor finishes/ventilation & model this using the ‘Undercut’ parameter. It works to some degree but it’s obvious from the finished result, that the programmer has never fitted a door & frame.

It would be unusual to install a new (slightly different for refurbishment) door & frame, then cut the leaf to suit the opening within the frame. Normally the frame would be made/installed to suit a standard door leaf size with allowance for fitting & final floor finishes.

So in correct modelling terms, the frame head height = undercut + door leaf + fitting tolerances + frame thickness. At the moment, this isn’t how it works & ‘bodges’ have to be made to get it to model correctly e.g.

• Set undercut to required amount (this ensures frame extends to the floor), then add the same undercut amount to the leaf height to ensure correct frame head height (important for understanding lintel/beam levels/intersections with joist/clearances etc). However, by doing this, a schedule would report the wrong leaf height due to the undercut added earlier. We could correct this by using a property/expression but we don’t have access to library part parameters e.g. undercut, so we’d need to create an undercut property & input this here also. Complication & repeating parameters only leads to errors & inaccuracies…

• As option 1 but instead of adding the undercut amount to the leaf, add it to the ‘Tolerance Upper’ parameter. Although this would show the top of frame head at the correct height, it increases the thickness of the frame head by the added amount (it should add a gap as it does for the side tolerances but adds it too the frame instead!). Graphically, the door frame shows incorrectly in section and positions of any inner/outer casings adjust by the Tolerance Upper amount.

• Set door above floor level by undercut amount required then set Opening Oversize lower parameter by same amount. This ensures frame head at correct height & schedule reports correct leaf height. However, the frame does not extend through the oversize section to the floor level, so is noticeable in section & model.

IMHO it would be better if the undercut parameter lifted the door leaf instead of cutting it. As far as I can tell (please correct me if I've missed anything), this should give the ability to accurately model both new & refurbishment type situations.

As mentioned by Scott, there are work arounds to ensure the correct reporting of heights, dimensions & schedules details etc but maybe we wouldn’t need these if the program allowed us to model these elements correctly…

[Erwin Edel]

Yeah, I prefer the model of the door frame to be correct. Fortunately we've never needed more than 30 mm.

I will come here to complain when we find a client who wants cobble stones for their floor finish

We typically do not model the floor finish (i.e. carpet, wooden floors, tiles, etc) or any other finish (plaster and so on) for interiors, as we need our dimensions to reflect what the folks on the building site need to construct, not what it will end up being when the finishes are applied. So using the offset, will result in floating doors in my sections.