Mastery Charter Schools engaged O Z Collaborative (formerly BWA) to explore options for expanding public and classroom space for this elementary charter school in southwest Philadelphia. Out of three options presented by our team, Mastery—in collaboration with the School District of Philadelphia—chose to move forward with the design and construction of a 2,300 square-foot addition to serve as a half-gym/multi-purpose room. The final design includes column supports to align the addition with the first floor, which is above street level, and provide minimal impact on the existing site.