I love your concept, man. I like the mix of wood and concrete, gives a brilliant re-used impression. I was going to suggest doing something to the walls too. I think maybe a drybrush with a lighter colour would bring out the texture a bit more, they look a bit bare compared to the rest of the structure at the moment (although that does draw attention to the fortification on the top*). Adding a little detail (such as a generator, as you suggest) would really help to break up the flat panels. For something less time consuming you could stick a few of those cool planks on here and there where the Orks have patched up some of the worst battle damage. (Is that scored balsa you used for the wood?)
Also, try a little filler around the area where the base joins the building to seal the gap and make the building look like it is sunk into the floor, unless you are meant to be able to move or remove the building, in which case, keep it as is.
So far so good, Looking forward to the finished product!
*Was trying to think of a way to meld the words Ork and fortification here, but could only come up with forkification, which sounds more like being attacked with kitchen utensils.
Last edited by jpunk; 04-15-09 at 10:21 AM.