Boundary representation

I have created an ifc importer for my company software.
I have imported all the entities(beam,wall,slab ec.c…)with the extrusion solid representation.
Now i must import brep geometry, but … there is a problem:
my software take as input only extruded 3d models, for example:
for a beam i extrude the 2d profile in 3d for a defined lenght ecc…
Is possible convert Boundary representation to a more simple extrusion form?
there are opensource software that can aid me with these complex representation ?
and for boolean operation?