There is never only one way to skin a cat.
How you model anything depends on what you want to do with it.
Do you need it to show up in your schedules correctly? What kind of info do you want to extract from it, does it need to look good in a floor plan and in 3d or is this just something for makeing a 3d view??
You can model the fascia and trim with roofs, rafters, slabs, mesh, .gsm,
For modeling the fascia and trim I typically use roofs. I drag a copy of the roof over 1 1/2", split and delete the part I don't want. Then change the depth of the 1 1/2" wide roof to 5 1/2" deep. Now its my subfascia. I drag a copy of the subfascia over, split it down to 5/4", change it to 7 1/4" deep and thats my fascia. Do the same for the drip edge and trim, and so on...
I use a roofs for the fascia, subfascia, and drip edge of the level edge of the roof also so everything cleans up very well.
There are more ways to do this than I care to describe.
My advise no matter what method you use is to model it just like you would build it, and in the same order it will be constructed in.
ArchiCAD 25 7000 USA - Windows 10 Pro 64x - Dell 7720 64 GB 2400MHz ECC - Xeon E3 1535M v6 4.20GHz - (2) 1TB M.2 PCIe Class 50 SSD's - 17.3" UHD IPS (3840x2160) - Nvidia Quadro P5000 16GB GDDR5 - Maxwell Studio/Render 5.2.1.49- Multilight 2 - Adobe Acrobat Pro - ArchiCAD 6 -25
