Adapting local San Francisco vernacular with contemporary sensibility, this split-level 4-story new infill apartment building and condominium maximizes building area on minimal lot with expansive circulation spaces connecting street life clear through to rear roof-top open spaces. By creatively interpreting local zoning codes (bay window, awning, cornice, and balcony) we generated a unified building facade with unique character that challenges the traditional urban fabric. Angular exterior metal surfaces wrap around and through large panels of glazing on the interior and exterior confounding spatial and perceptual boundaries. Designed to weather from black to soft grey, zinc panels mark the passage of time on both the warm textured interior and cool-roof patterned metal exterior. As a Black Mass the building form is at once negated while simultaneously revealed through light of day and at night as provocatively complex.