Willis Tower largest office building to earn Energy Star certification

Willis Tower largest office building to earn Energy Star certification

Photo courtesy of Willis Tower

Chicago’s iconic Willis Tower has earned Energy Star certification, becoming the largest office building and the third largest building overall to have the designation, according to property manager Equity Office.

Willis Tower, previously known as the Sears Tower, was originally constructed in 1973. Owned by the Blackstone Group, the building is 110 stories tall and has more than 4.5 million square feet of space. Currently more than 100 businesses are located within the tower.

Equity Office says that Willis Tower improved its energy performance by managing energy strategically across the entire organization and by making cost-effective improvements to the building.

Infrastructure retrofits and energy management practices included:

  • Retrofitting HVAC, which included solar window filming, air infiltration points, and exterior air damper banks
  • Adding motion sensors in all mechanical areas and some common areas
  • Adding lighting control panels in tenant areas to help reduce lighting operation in areas not in use
  • Retrofitting lighting to high efficiency LED fixtures and lamps in building common areas, main lobbies, mechanical floors, and elevator cabs
  • A building-wide upgrade of the building automation system for more efficient temperature control, HVAC sequencing, and energy monitoring to allow for demand response opportunities.
  • Replacing antiquated variable frequency drives and installing new VFD drives on equipment that communicate with the BAS so managers can ID opportunities for energy conservation
  • Modernizing around half the building’s chillers
  • Retrofitting all the cooling towers

Earning Energy Star certification for a commercial building means that Willis Tower uses an average of 35 percent less energy than a typical building, and that it releases 35 percent less CO2.

The 2017 National Green Building Adoption Index released in July found that Chicago had the most building spaces with LEED and Energy Star certification in the United States among the country’s 30 largest real estate markets.


Topics: Associations / Organizations, Building Owners and Managers, Certifications, Great Commercial Buildings, Healthy & Comfortable Buildings, HVAC - Heating, Cooling, and Ventilation, Indoor Air Quality (IAQ), Interiors, Lighting - Energy Efficient Lighting, Office Buildings, Solar Energy & Solar Power, Sub-Flooring, Technology, Thermal Envelope - Building Envelope, Urban Planning and Design, Ventilation, Windows - Glass and Glazing Strategies and Systems

Sponsored Links:

Latest Content

Find Us On:


Get the latest news & insights