This is the pump house, where raiders and ravagers fly over to fill up on energy. I've modelled the walls to give the effect that a squad of Harlequins or other warriors armed with grenades have blown a path through the walls.
I've already blown up a dreadnought using this as a detonation charge building.
This is a slave factory, where orks and kroot slave away making loads of weapons and armour... well before they dropped a load of frag grenades on top of it!
The wind turbines were added to give the building that old warehouse feal. I made the floor so that you could still position snipers and heavy weapons teams out of reach.