Exterior image of the United Therapeutics Unisphere project in Silver Spring, MD.
A: Image of man working at laptop. Smart windows provide glare control behind him.
Smart windows tint to provide solar and glare control in open office spaces.
Signage is installed throughout the building to educate occupants about the sustainable technology contributing to net-zero.
United Therapeutics
Ewing Cole
SageGlass Classic
Project Size
5,200 Ft² / 483 M²

The 210,000 square-foot, elliptical “Unisphere” in Silver Spring, MD is home to biotechnology leader, United Therapeutics and is one of the largest net-zero buildings in the world.  Employing multiple sustainable technologies to produce its own electricity and thermal energy, the site has no operational carbon footprint and supplies excess power back to the utility grid during peak production times. 

  • The site leverages 3,000 solar panels to generate 1,175 MWH of energy annually while a quarter-mile underground labyrinth acts as a natural ventilation system between air and earth to cool the building.  Plus, an atrium pool serves as a heat sink.  

  • The building leverages a daylight harvesting strategy to minimize the use of artificial lighting and reduce energy usage.  Electrochomic glass tints and clears throughout the day to maximize daylight without unwanted glare.

  • Smart windows provide thermal control, reducing the amount of heat entering the building and improving energy-effiency, while delivering a comfortable work environment. 

The building also includes a sundial-like Energy Wheel which communicates energy usage patterns in real time, indicating when the building is producing a surplus of energy or when it is using more energy than it is producing.  This serves as a cue to occupants to adjust their energy use when needed.