Ive been spending a bit of time lately studying the modular buildings of many games and reading/viewing several tutorials about it as well, but almost every example I see uses a plain square building that does not have any angled roof or similar.

In all my applications (CS6, Blender/Max, UDK) I adhere to the same grid spacing and I get pretty good results, but trying to make modular angled pieces is confusing me as I'm not sure the best way to approach it.

Below is some shots of my template sheet and workflow I have been doing. Should I do the roof separately or is it possible for me to keep it in the same texture sheet?

The main issue is below. I have made a couple modular roof pieces but when i try to use them, i end up needing to model multiple other parts to fill gaps based on what roof shape i want. I then model those 'filler' pieces and now i have that much less space left in my texture sheet and those pieces are usually not that reusable for anything else. This is where im not sure how to proceed.

If anyone has any links to documents or papers talking about this or advice, I would greatly appreciate it! =-)

My main roof pieces with the gaps

My power of 2 texture sheet, with 16x16 grid squares.

The texture sheet loaded into blender on a 16x16 plane and starting to separate and extrude.