IFC is static? Far from it!
Let me introduce the IfcParameterizedProfileDef: a class that lets you describe basic profile geometry just by a few attributes.
Only basic ones? Let’s have a look:
IfcCircleProfileDef: what defines a circle? A radius. Well, the IFC knows that. Change the radius, and the model changes too. It’s actually that easy.
IfcRectangleProfileDef: Same for a rectangle. You don’t need to define the coordinates for each corner. Width, height, you’re done.
You know what’s even better? There are definitions for hollow and rounded rectangular profiles as well (among many others). Use the corresponding classes and add measurements for the outer and inner rounding and/or wall thickness. If done correctly a hollow rounded profile does not really increase the file size much (displaying it in the viewer might get a bit slower. Not sure if you would notice it, though. Graphic cards can even handle crappy models quite well).
There are also other profiles, even more complex like I-shapes. Still, they can be defined in one line, including web thickness, fillet radius and flange slope.
Have a look here to see all the parameterized profiles available in IFC4 (most of them also in IFC2x3).
They are the base of clean, dynamic #openBIM models.