topic Re: Lifting the limitations of Dormer Shed library in Libraries & objects

Lifting the limitations of Dormer Shed library

Mike96 — Sun, 24 May 2026 18:29:25 GMT

I've got a problem with the native Dormer Shed in Archicad 25 and 28. I think its maximum Shed Roof Pitch value (screenshot) is hardcoded at 35 degrees. This is highly impractical and illogical limitation, and it should be increased to something like 89 deg. Sadly, I can't edit GDL myself, so I'm hoping someone would be able and so kind to try fixing it.

I placed it as skylight but the issue is the same if placed as an object.

Sorry for Polish UI but I don't think this will be a problem.

Attached test model. Should I upload PLA or is PLN enough? Anyone can also start from scratch, it's a super simple example.

Operating system used: Windows 10

Re: Lifting the limitations of Dormer Shed library

Mike96 — Fri, 22 May 2026 20:45:19 GMT

@Jaime-airc_digital,

maybe you want to take a look at it? I saw you got some experience with GDL and dormers :]

Re: Lifting the limitations of Dormer Shed library

Karl Ottenstein — Sat, 23 May 2026 15:24:05 GMT

In 25+ years, I’ve never used the dormer objects vs modeling the dormers structurally/fully. The objects are cute for demonstrating Archicad but, in my view, have no place in producing meaningful construction documents and data reporting.

Re: Lifting the limitations of Dormer Shed library

Mike96 — Mon, 25 May 2026 05:46:51 GMT

Well, they certainly are not perfect for 2D documentation but sufficient for 3D presentation and that's what I need right now (and pretty often, too). I work with heritage architecture on a daily basis, producing both 2D docs and 3D models, and not gonna lie, these objects speed up roof modeling significantly, until... You need steeper roof.

Why even keep such libraries in database when they have such weird limits imposed? It's not like a feature missing, it's not underdeveloped. I don't know what the author had in mind: "hmmm, no one would surely use a dormer roof above 35 degrees, so let's make it a limit!" ?

Re: Lifting the limitations of Dormer Shed library

Botonis — Mon, 25 May 2026 07:43:17 GMT

Using objects to create complicated construction elements is not always the best decision.

Using a basic approach might take a liitle more time but sure it simulates the real construction with all the BIM advantages.

There is also this by b-prisma for dormers:

https://b-prisma.de/object-shop/product_info.php?products_id=126

Re: Lifting the limitations of Dormer Shed library

Mike96 — Mon, 25 May 2026 13:54:05 GMT

Judging by video demo (PDF manual link is broken), I'm not sure this will help me. And I need to be sure before spending money on another object. I've already spent some on objects that didn't help me. Do you use this object personally? Would you recommend is as applicable in my case?

Also, I appreciate y'all telling me what's the best decision / approach and what's not but I've been using Archicad, along with some other modeling programs, for almost a decade and believe me, I know the pros and cons to different workflows.

I don't care that much about 2D drawings or BIM advantages. I mostly produce 3D models, many of which never get turned into documentation or BIM compatibility is not required. In the end of the day, it's easier to manually fix a flat drawing than a model.

"Using a basic approach might take a little more time" already used too much of my time over those years, which wouldn't be a problem if Graphisoft took a little more care in creating their libraries. I see them as great yet not fully explored (I don't wanna say: wasted) potential. They are flawed but still extremely useful in so many cases.

As far as I understand, this is fixable and could be done once for all. One fix and no more annoyance for life.

Re: Lifting the limitations of Dormer Shed library

Botonis — Mon, 25 May 2026 15:07:56 GMT

If you prepare just 3d models then obviously depending on libary objects sounds logical.

When you create analytical construction layouts, quantity extractions, cost calculations, static frame caclulations, and using strucural detail options, design options, graphic overrides etc. then objects don't always perform as expected....

Different needs, different workflow.

Re: Lifting the limitations of Dormer Shed library

Jaime-airc_digital — Mon, 25 May 2026 21:12:07 GMT

Yes, the limitation is a safeguard, but it can be removed... here is the link to the edited object.

You just need to modify the ranges from the parameter script and the hardcoded reset for the shed angle in the master script.

Re: Lifting the limitations of Dormer Shed library

BrunoH — Tue, 26 May 2026 07:06:00 GMT

Hi Mike96,

You are wrong, as the limit is a calculated one. It is calculated as Roof Angle° - 5°

No need to edit the object.

This object shall be place on a Roof and need the Roof Angle to calculate some of its parameters.

And after that the Roof Angle may be changed and the object shall recalculate its parameters and insure coherent ones.

When you open the tool options, the object is'nt already place in a roof and it can't read the Roof Angle so the limit is calculated with the default value set in it. The default value is set to 40° that's why at first the limit is 35°.

So if you place the object on a roof with the Roof Window tool, place it first on the roof, select the placed object and open its options, the 35° limit should have been changed.

If you place the object with the Object Tool, there's no Roof Angle to read, so you'll have to set it first yourself, in the All parameters dialog off the object (see images).