Quick Question about Modular Buildings

So I have a quick question, what would be the best way to go about creating a modular building set where you can change the interior & exterior of the building? Just curious you see as I’m wanting to have a go at making such a system but I’m just struggling to figure out what might be the best way to approach such an idea.

Any help would be greatly appreciated!

Thanks

It depends on what you want to change, if the modeled details are changing then for each change you want to make you need to make sure that the mesh is a separate mesh so that it can be switched out.