I have a project that is going through site plan review and the PC is determined to impose a 20' buffer zone in the "back" of the property. The property runs through a city block in a CBD and abuts a residential district in the back. Currently, there is a 3' setback for buildings and no landscape buffer requirements. The City has been "updating" the Master plan and states that they will not pass my project unless I put in a 20' buffer. The updated master plan will institute a 20' setback. I've submitted a plan for dense wall of 10' tall arborvitae along the back of the property- close to the sidewalk. I also would like to place an acoustic barrier/wall behind the arborvitae in order to attenuate the sound from the rear of the property (I plan to host small events in the back). The City and the PC believe that sound attenuation and sound barriers do not work... despite the fact that I've hired a highly qualified acoustic engineer and have submitted detailed technical specs. They also do not want me to put up the acoustic fence and would rather that I put in a 20' landscape buffer instead. All the research that I've read states that a 20' buffer will do little if anything compared to the acoustic barrier (30db). On top of this, I can't afford to lose 20' of useable space in the back of the property. Any recommendations? Any research papers, case studies, to help my case? Thanks!