there are generally two types of infill opportunities in california: 1) infill in high-demand markets, like san francisco, santa monica, and berkeley, that requires virtually no public subsidies and 2) infill in blighted neighborhoods, like hollywood or old town pasadena in the 1990s or downtown oakland today, that need major public investment to attract sufficient private capital.

building in the high-value areas is often restricted by wealthy and organized neighbors. the classic example is the area around the rockridge bart station in the bay area, where berkeley neighbors have stymied development that could concentrate new growth around the multi-billion dollar rail line running through the neighborhood. as a result, many infill developers have had to look to low-income or industrial neighborhoods to build projects. these neighborhoods often lack neighbors entirely (such as much of downtown los angeles before the recent boom) or the existing residents are unorganized and unable to fight proposed projects. building in these spots typically requires major investments in infrastructure, schools, and public safety. redevelopment is key to financing many of these investments.