3D free bock mesh type with structured Hexa
 

I meshed a building in a domain with the Hexa blocks method. There are holes in the building forming through-building openings. Now I need to change the mesh inside the hole to one of the free types such as "all tri","hex-dominant" and etc.. I converted the mapped to free and used "3D free block mesh type". I do not know how to construct the volume mesh now. When I check using the cut plane there are just surfaces that are meshed, not volume. Also, there are walls inside the hole that I want to use prism on them.
Can any one help me?
Building:
http://i68.tinypic.com/8zqxpw.png

Close-up:
http://i68.tinypic.com/2j5nmtd.png