Problem with buildings

Hi all, and HAPPY NEW YEAR!!, hope everyone starts with the right feet!!, first all sorry but my english is not perfect, so, thanks, my problem is this:

Im trying to create a house/office building with destructible meshes, the problem is i was importing some 3D houses from PhysX Lab for tests and i cant go inside and walk, is there a way to create a house for example, in google sketchup (im using this one because its pretty simple) so i can walk inside and them, export to PhysX Lab to make it a destructible mesh and export it to the engine and add it a collision stats to walk inside and destroy it at the same time, or i must build it INSIDE THE UNREAL ENGINE using the statics meshes, 1wall then, another wall, then the roof, etc?, hope you can save me A LOT OF TIME to build my level, peace!.

Resume:

I want walk inside a house, and destroy a wall if i want with my RPG, or 2 walls or the entire house to the ashes!