These habitation blocks started out as O-scale train hobby buildings, with loads of detail added. The one on the left is made from DPM brand modular building panels. The right one is made from a K-line Fire House kit. Both have custom roofs. Pipes, wires, steel plates, and skull details were all added.
To paint them, I primed them with flat black spray paint, then drybrushed them with brown, red, and tan. Metal pipes and plates were drybrushed with steel, then washed with rust and light brown.