Throughout New York City, students from Pre-Kindergarten through 12th grade are learning firsthand about "co-location," the practice of two or more distinct schools existing in the same building and sharing spaces. While some co-locations involve multiple public schools, this paper will focus on co-locations with charter schools in public school buildings. All too often, co-location in New York City has led to the denial of parity and equity for all of the City's public schools students. This paper discusses best practices that are absolutely essential to prevent co-location practices that are unfair and deny parity to all public schools students. These best practices will improve the process of co-location in New York City.