Apartments take a few months to build. There are standard designs they build over an over again in different locations. I realize CA has earthquakes and maybe cannot take a design from Ohio (though I wouldn't be surprised if they could), but there should be plenty of designs that meet codes. If they cannot build thousands of apartments in a year the problem isn't the time it is they are doing something to make it not possible to build that fast.
Building should be by right - no need to ask the neighbors for permission or get a review (for a standard design that doesn't do anything unusual), just half hour to get the permit and then a few routine inspections along the way.