Here are some photos of an O scale Coal fired Boiler house I am building out of 3mm styrene where it sits on the layout is in the Steel Mill thread at the 2-rail section this is just about building it.
It really is a very simple building what makes it stand out from just a simple "Box" is the details on the outside like windows and doors plus an office and what looks like a building for the stores. I never detail the interior unless you can see them from the aisle even then I hesitate I have many other projects to do.
The finished model will end up at the Steel Mill thread on the 2-rail page.
Thanks Roo.