A few weeks a client of long standing came to me with a problem concerning his property in La Jolla (San Diego County) Ca. My client owns 2 duplexes in Zone 5, a residential zone where setbacks are required, i.e., areas on the inside of a property’s border where no building can be placed. However, his property abuts Zone 4, a commercial zone not requiring setbacks. The SD Co. Bldg. Code provides for these circumstances requiring a 4 Ft “YARD” be placed inside the Zone 4 property’s interior border when abutting a Zone 5, a residential zone property. (See Ca. Bldg. Code §159.0307 (b)(3)) The neighbor is constructing a building in an areas supposed to be this Yard. Is this in violation of S.D. Building Code. If yes, what action (legal process) can I do to stop this construction?