Partial Demolition

It seems to never fail that in our remodeling projects we need to demolish part of an existing building.  Be it walls or roofs, part of something always needs to be demolished.  In the past we have just copied and split the roof or wall apart.  Today I built a Generic Model - Face Based component that is strictly a void.  I can then just snap this to the face of my object that I want to remove.  I can phase it then and everything appears or does not, as is should.