USPS On-demand is a revitalization of the current United States Postal Service, a partnership with Uber for a service in express local-delivery of packages and goods. Currently occupying Mies van der Rohe’s Federal Plaza building in Chicago, USPS On-demand reutilizes the space to improve and accommodate this additional service for USPS and Uber employees. Using Mies' 1921 Friedrichstrasse Skyscraperconcept, the design is derived by reversing the utilization of maximized transparency for greater exposure of interiors. Heavy cubic forms within the building divide the space into its sub-programs, achieved by using glass as masonry with different opacities. The goal is to achieve the appearance of constant transformation of space as different combinations of the subdivided glass offices, units, etc. come into ones line of vision, constantly changing in opacity and transparency depending on the relocation of ones viewpoint within the building that result in public and private spaces.