Hi @katsanosengineer , VDO below
"calculate the total side surface area". it depends on elements you want to calculate. Mostly, it is related with Bill Of Quantity (BoQ, QS) job. Let see some solution of each elements:
1. Structure foundation
1a. Isolate foundation: It has default parameters Width, Height, Foundation Thickness, Volume,... Then, we can use those parameters to come out formwork area using logic math formula. For rectangular/square shape, simply use
A=2*(Width+Height)*Foundation Thickness
It is not recommend to apply with triangle or polygon shape.
1b. Foundation slab: It has default parameters Perimeter, Plan area, Foundation Thickness, Volume,... Any shape can apply for surface area.
A=Perimeter*Foundation Thickness
1c. We also can use 3rd party plug-in like Graitec (https://www.graitec.com/Help/PowerPack_for_Revit/En/#t=Add_Parameters.htm) or SOFiSTiK (https://docs.sofistik.com/2024/en/bimtools/cmdref/formwork_areas.html)
2. Structure column It also has default parameters, but we need to shared parameters to schedule for logic math formula calculation.

3. Structure framing It also has default parameters, but we need to shared parameters to schedule for logic math formula calculation.

4. Floor Formwork area=Side formwork+Bottom area. Where Side formwork= Perimeter*Floor thickness. It is recommend to use 3rd party plug-in as they will include side formwork at opening area.
* Another method to come out formwork qty, we can run Dymano Visual Programming.
We need to test each elements with related methods. Compare with logic formula