United Therapeutic’s new headquarters is the one of the largest site net zero energy commercial buildings in the U.S. The one-of-a-kind building includes a high performance envelope, mixed-mode ventilation, and a quartermile-long underground labyrinth.
To support the project’s net-zero energy goal, Atelier Ten worked closely with the design team to integrate passive design strategies including a natural ventilation system with a labyrinth. The labyrinth utilizes thermal mass to passively moderate temperatures within the atrium without relying on mechanical conditioning. Outside air is drawn through a series of below-grade, concrete passageways that store thermal energy at night and moderate swings in temperature during the day. The atrium pool serves as a source of evaporative cooling and is used as a heat sink.
The building is designed with mixed mode ventilation, drawing air into the spaces through automated exterior vents and operable windows, and exhausting air at the top of the central atrium. Atelier Ten used bulk airflow analysis to design this buoyancy-driven natural ventilation system. Incorporating a solar baffle structure at the top of the atrium helped enhance the natural ventilation effectiveness and provided adequate daylight.
Atelier Ten collaborated with the design team on the building form to enhance daylight availability and natural ventilation. The high performance envelope includes electrochromic glass, operable windows, and daylight harvesting. With the addition of efficient HVAC systems, including chilled beams, ground source heat pumps, and on-site photovoltaics, the project generates 100% of its electricty on site.