This is my first post, I have researched numerous topics in this forum. I am preparing to build my first diorama, which includes a road and a ruined church building.

I have not found any information on the techniques used to paint a building. How do you paint ruined building? Thanks

jugernot, First I would like to say hello and welcome to Armorama. secondly there are articles in the feature setting about painting buildings Here is one such link
https://armorama.kitmaker.net//features/65
Looking forward to seeing some of your work. cheers Kevin

The way I did my Cold Stare dio (see my gallery, click below) is to give my stone wall a base coat of light gray, to make sure its all covered. Then I made a few mixes of different gray colors, and picked out each rock, then I went back in and colored the mortar in between a lighter color.
The key to any rock based wall is washing it. Make a very dilute mix of thinner and paint and wash the whole wall to tone it all down. Then vary the color of the wash mix with some burnt umber or dark brown gray or back and go in around details to add depth and shadow. Let the natural flow of the wash 'happen' and fill in the low points. Repeat as desired with various shades and thicknesses of wash(s).

I guess Scott already gave you one of the best advise you need to do in terms of building painting. The way I do it is similar to Scott, the only difference is that I usually start with Black. The initial black will somehow show depth and shadows for some of the crevices and recesses of the building. Don't worry if its too black coz, the washes will somehow lighten them.