Constructing a base
I took a piece of plywood in 35x35 cm, added a slice of Dow foam and a piece of a plaster board to create the concrete ground of the factory.
I construct the walls with plaster board adding some acrylic putty in the surface to create the tracks from the wooden molds in the concrete areas of the building. Painting in random khaki and grey colors with washes and some pigments

Then I  tried to add some ivvy plants on the brick wall. Roots made the stems and leaves glued one by one and painted in green colors

Windows and doors from plastic sheet