Yes, housing expenses, while away at college, are considered a qualified withdrawal from a 529 fund. But, the amount is limited to the amount charged by the college. For example, if your son pays $1000 per month and the highest priced dorm room is $500, you may only count $500 as a qualified expense. You may not count the months he's not in school (summer break if you pay rent to keep the apt). The same rule applies for off campus board (meals)