Applying different shader based on connectivity

I've got one piece of geometry (a house) which is modeled from multiple separated pieces but combined together in Maya to make only one mesh. I'm trying to figure out different ways of applying shader variation without pre-processing (aka splitting the object manually), in Houdini for example I might use the connectivity function to see which triangles are connected together and then use that as a ID for applying a randomised shader.

The obvious things are changing shader based on world normal, dot product towards camera, or distance to camera, but does anyone have some smarter ways in mind to create more static type of variation?

Best,
Arttu