It could be that when you build a 4th living quarter that completes a 2x2 square, the 4 blocks become a larger "giant living quarter".
edit: In fact it's possible to give a bonus for adjacent facility of same type, and build (little by little) a lab which is 3x1, or L-shaped, or Z-shaped etc. But then somebody has to map the 13 extra variants for each facility block. Huge work, but then we get more interesting maps with more 'large' rooms.