Hi shokan, I would need to get some more information about the house model to answer that properly.

Would the house be constructed in MoI as a single solid, like with the roof and chimney all booleaned together into one single piece? Or would those be separate objects in MoI?

If it is all booleaned together into a single solid in MoI, then when you export to a polygon mesh, it will also be one "mesh object" in the polygon file as well.

If it is made up of multiple different solids, then it will become multiple mesh objects in the output file. However, you can control this by assigning names to multiple objects - if several objects have the same name then when exported as a mesh those will be combined into a single mesh object.

But I'm not exactly sure what your concern is - normally in a polygon mesh program there are facilities built in to separate polygons from one another, so you would be able to edit different portions of the model if you wanted just with the mesh app's regular toolset...

- Michael