Nice to hear that you like it, jymmy!
Sure you can have some recipes.
The white of the walls:
1) black sprayed undercoat for the whole building
2) white undercoat applied by big and broad brush. It doesn't have to be neat and it's okay if you see some black through the white. In fact, it helps to get a dirty finish
3) heavy drybrush of bleached bone. No neatness required and it does not have to be bleached bone near the edges (where it is next to stone or wood for example), because in a later stage I put washes of browns and black on there.
4) apply a thinned down flesh wash. Again, this does not have to be neat of cover the white completely.
5) heavy (and uneven) drybrush of bleached bone
6) very light (and uneven) drybrush of white
7) weathering with several layers of very thinned down browns, blacks near the edges, and stripes below windows (rainfall), etc. and some swipes of thinned down green (moss) on some places
wood
1) black sprayed undercoat for the whole building
2) heavy drybrush of darkbase dryad
3) heavy drybrush of gorgoth brown
4) light drybrush of vermin fur
stone
1) black sprayed undercoat for the whole building
2) heavy drybrush codex grey
3) light drybrush of fortress grey
4) weathering with several layers of very thinned down browns and blacks near the edges and where it touches the ground
5) some swipes of thinned down green (moss) on some places
metal
1) black sprayed undercoat for the whole building
2) paint boltgun metal
3) heavy wash of thinned down flesh wash
4) wash of nuln oil
5) highlight boltgun metal
6) light drybrush of mithril silver
Hope this is helpful.