Check out Habitat 67 in Montreal - an architectural student solved this in the 60s. Apartments where everybody gets their own rooftop terrace. Given the funding, the original plan was for a 30-story terraced hill of mixed-use and apartments in an A-frame with public green space underneath that mixed the density of apartments with the benefits of single family homes.

Since everybody thought he was crazy, he only got a fraction of the funding for what he ended up building for the 1967 World's Fair, but those apartments have the longest occupancy time of any building in Canada (some seeing 2 or 3 generations living in them) and a 5-year waiting list on units.

Last year, a 3d model of the original concept was released for Unreal Engine: www.unrealengine.com/en-US/hillside