I have done homes as large as 14000 square feet, and i find that keeping each room to its own circuit is best. Especially since most costume homes floor plans always seem to change. This does not include rooms that have multiple recess cans, obviously some rooms may need more than 1 ckt. I try to keep 10-13 openings per circuit. Also, In reply to scot35, I will take a set of plans to a printing place and have them remove all but the exterior wall and then I fill in acording to my layout....cost is 5$per page but it is worth it