Winthrop Center Officially Certified as the World’s Largest Passive House Office Building

Winthrop Center, Boston

BOSTON – Millennium Partners hosted Boston Mayor Michelle Wu, Massachusetts Secretary of Energy and Environmental Affairs Rebecca Tepper, and Massachusetts Climate Chief Melissa Hoffer among other city and state officials for a globally historic event as Winthrop Center was honored as Boston’s most energy efficient building, receiving official certification for its office floors as the largest Passive House office building in the world. 

Meeting the rigorous requirements of the international Passive House Institute (PHI) certification standard, which provides third-party verification and quality assurance that the building meets the high performance and comfort levels of Passive House design, Winthrop Center’s office space shines a light on Boston’s leadership position in addressing climate change and will advance adoption of high-performance passive building as a mainstream market standard.

“The esteemed Passive House certification for Winthrop Center’s office space marks an important milestone not only for Millennium Partners but also for the City of Boston,” said Millennium Partners Founder Christopher M. Jeffries. “Nearly seven years ago, we were chosen to redevelop a city-owned parking garage in downtown Boston. Now the bold vision has finally come to fruition, resulting in a true building of the future, and something we can all be proud of.”

Located in the heart of Boston, Winthrop Center sets a new global standard by integrating health and wellness, enhanced productivity and social engagement, and advanced technology and sustainability into the building design. The mixed-use development comprises 812,000-square-feet of Global Class A office space designed to rigorous Passive House principles and 510,000-square-feet of residential space, including 317 residences. Winthrop Center was designed by Handel Architects in collaboration with Steven Winters & Associates and SOCOTEC to incorporate major elements of Passive House design in its office portion. With a well-insulated building façade, air-tight exterior envelope, and advanced energy recovery ventilation (ERV) system, the office design results in significant energy savings and superior indoor air quality and comfort.

A typical Class A building in Boston’s existing stock uses 150% more energy and existing LEED Platinum buildings in Boston use 60% more energy than Winthrop Center’s office space.

 Its official Passive House certification advances Boston’s leadership position in addressing climate change. Cities and states adopting carbon reduction strategies are increasingly interested in Passive House as a design standard for the future. Massachusetts recently implemented building codes that align with the Passive House standard, including compliance paths for Passive House as well as Passive House components in its energy code (Stretch Code).

The commemorative ceremony was held in The Connector at Winthrop Center, a multi-floor public gathering space that serves as Boston’s new civic landmark. Creating a sense of community and inspiring appreciation for the arts and Boston’s rich culture, The Connector welcomes Winthrop Center residents, office workers, and locals to gather in a globally significant building setting a new standard for building design. Inherently civic in scale and function and measuring 240 feet long, 65 feet tall by 50 feet wide, The Connector is designed to educate, entertain, and engage the public throughout all seasons while advancing social and cultural engagement for Winthrop Center’s residents and office workers.

In line with The Connector’s cultural programming, the event also included the unveiling of a new grand art installation by renowned artist, Dale Chihuly. Titled Vermillion Fiori Installation, the composition in glass hangs from The Connector’s soaring ceiling, comprising the asymmetric, swirling patterns of the “Persian” form in hues of red and orange. Molten glass, ringed by linear wraps, is plunged into optic molds to create the dramatic forms, which for Chihuly, are an exploration of form and color with an ancient sensibility.

“We’re proud to create an inspiring and climate conscious building with beautiful publicly accessible art and cultural programming for all of Boston to enjoy,” added Jeffries. “Winthrop Center marks the pinnacle of Millennium Partners’ three decades of experience fostering community and redefining wellness in the built environment.”