Modular Wall (Partial)Texture Variation


I work on a concept by Tony Holmsten(attached) and am stucked with the creation of the walls.
As you can see I intended to create them modular meaning splitting each wall section into three pieces as shown in the attachment.
This would be no problem but I don’t know how to change the painted part of the wall. As you can see it remains the same wall just this specific area changes. Either I parametize in the master material settings the texture so I create three variations where I only change the painted part, which would work but its a dirty way… Or I make a single wall mesh with a e.g. 4096x1024 texture, which I despise as well.
The same applies for the ceiling ofc too.

What’s the best way to solve my problem?

Kind Regards