Designing mechanical systems for a transit-oriented development means solving for a grocery store, retail spaces, a parking garage, and 42 distinct apartment layouts all in the same building envelope at the same time. G&W provided mechanical engineering design-build services for this St. Louis TOD, designing DX split systems for each apartment unit and coordinating dedicated outdoor air systems ducted throughout. HVAC load calculations, ADA unit layouts, construction documents, and signed and sealed permit drawings were delivered for both the north and south buildings.