Single family homes that are now being rented by a big group of students. Often noisy. I have thought that denser zoning might be able to improve this situation, ironically. Instead of "single family" zones, allow the big houses to be broken up into several studio apartments. It's harder to have a big party in a studio apartment.
Density is better for the environment, in more ways than one.
Studio apartments for studious students. How's that for a slogan.