Material and texture pipeline for modular assets

I'm looking at setting up a very simple version of Bethesda's modular asset workflow, where interior spaces are assembled from kits of wall/floor/ceiling pieces with a uniform size and scale. I'm not working about poly count since the levels are pretty moderately-sized and the actual meshes are often quads or cubes, but I don't want to blow my GPU up with tons and tons of material and texture instances.

So how should I be setting this up? Right now each version of a wall/window/whatever is a prefab variant of the base mesh with a different material and texture, is there a way I should be batching these together?