Greetings from Taiwan! Our project is located in a science park that does have requirements for "open space" and "green space," which would indicate that we employ Case 1 to achieve this credit. Problem is, the local requirements for those areas are not consistent with LEED. For example, the locals generally define "Open Space" as anything outside the building footprint, while "Green Space" as any vegetated area on the site. Obviously using the 125% of local open space requirements calculation wouldn't make sense, as the intent of this credit greatly differs from how the locals' define it.
So, despite the existence of local "zoning" with open space requirements, my inclination is to go with Case 3, where there is local zoning but with no open space requirement. Is this sound reasoning, or can anyone fashion a better way to approach this?