3 or 4 plexes are not going to solve the housing issue in the bay area, because many single family homes are already being used that way. They need to build den

3 or 4 plexes are not going to solve the housing issue in the bay area, because many single family homes are already being used that way. They need to build dense urban cores with residential high rise and mixed use mid rise. Ideally close to Caltrain and BART stations, but additionally every single family zoned neighborhood should be given such an urban core. That way it would create more dense pockets all throughout the area, which would make it possible to bring alternative modes of transit into all neighborhoods by connecting these dense pockets with rail, bus routes and bike lanes.