Millennium Partners Secures New England's Largest-Ever Commercial Property Assessed Clean Energy Financing for Winthrop Center

August 14, 2026

Kelsey Schiller, MassDevelopment
857-325-3477
kschiller@massdevelopment.com

Lesley Osborn, Nuveen Green Capital
+1 475-291-6346
Lesley.osborn@nuveen.com

Erin Wickman or Emily Nixon, Glodow Nead Communications (on behalf of Millennium Partners)
415.394.6500
MillenniumPtrsPR@glodownead.com

BOSTON – Today, MassDevelopment, Nuveen Green Capital, and Millennium Partners announced $281 million in private financing for the Millennium Residences at Winthrop Center in downtown Boston under the state’s Property Assessed Clean Energy (PACE) Massachusetts program. This project represents the largest commercial PACE financing to date in New England.  

Developed and owned by Millennium Partners, Winthrop Center was designed as a new standard for sustainable urban development, combining the world's largest Passive House office building with public gathering spaces and residences. Passive House is a rigorous building standard designed to significantly reduce energy use, particularly for heating and cooling, while maintaining a comfortable indoor environment.

The financing allows Millennium Partners to capitalize on the building's industry-leading sustainability investments and reinforces Winthrop Center's position as one of the world's most environmentally advanced mixed-use developments.

“This historic financing for Winthrop Center will help residents and businesses lower their bills by reducing their energy usage, while supporting continued economic growth in downtown Boston," said Governor Maura Healey. "Through PACE Massachusetts, we’re bringing private investment to the table to support major developments and make our buildings cleaner and more efficient.”

“Projects like Winthrop Center show what’s possible when the public and private sectors work together to invest in our communities,” said Lieutenant Governor Kim Driscoll. “PACE Massachusetts is helping unlock private investment for projects that strengthen our economy, revitalize our downtowns and make our buildings more energy efficient. We’re excited to see this program continue to grow and support more projects across Massachusetts.”

“Winthrop Center shows what’s possible when ambitious development is paired with smart financing tools,” said Economic Development Secretary Eric Paley, who serves as Chair of MassDevelopment’s Board of Directors. “Through PACE Massachusetts, we’re helping developers tap into private capital to make long-term investments in energy efficiency while continuing to invest in the buildings and places that drive our economy.”

Administered by MassDevelopment in consultation with the Massachusetts Department of Energy Resources (DOER), PACE Massachusetts enables commercial property owners to fund investments in energy efficiency and renewable energy projects in new construction or existing buildings at a lower cost by agreeing to a betterment assessment on the property. Through PACE Massachusetts, Millennium Partners will recapitalize and extend the financing term for The Millennium Residences at Winthrop Center using permanent, lower-cost financing from capital provider Nuveen Green Capital and will repay the financing via a betterment assessment on the property.  

“Winthrop Center is helping to set the standard for sustainability and energy efficiency,” said Boston Mayor Michelle Wu. “We’re grateful to have a clear proof point that investing in green technologies and efficient building performance goes hand in hand with reducing long-term operating costs, and reaching our climate goals for a healthy, beautiful city.”

“The Millennium Residences at Winthrop Center is the Taj Mahal of Passive House!” said Climate Chief Melissa Hoffer. “This PACE climate financing from MassDevelopment illustrates how the state can partner with developers to advance cutting edge approaches that will become the commonplace standards of tomorrow.”

“MassDevelopment is excited to see The Millennium Residences at Winthrop Center recapitalized through PACE Massachusetts, representing the largest commercial PACE financing in the region to date,” said MassDevelopment President and CEO Navjeet Bal. “We congratulate Millennium Partners and Nuveen Green Capital on today’s transaction and encourage developers and property owners across the state to explore how this financing tool can help them advance clean energy investments, lower building emissions, and save money.”

“It’s no surprise that the world’s largest Passive House office building – and the most sustainable building in the northern US – was built in Massachusetts. Winthrop Center will use 65% less energy than similar, non-energy-efficient buildings in the region,” said Department of Energy Resources Commissioner Elizabeth Mahony. “PACE provides a pathway for property owners to make cost-effective investments in clean energy and energy efficiency that pay dividends by reducing monthly energy costs for families and businesses, and reducing the burden on our electric grid.”

"This landmark project is a powerful example of how Commercial PACE (C-PACE) financing can transform commercial developments," said Mike Doty, Senior Director of Originations for Nuveen Green Capital. "We were honored to partner with MassDevelopment to recapitalize the largest C-PACE-financed project in New England, one that has helped reshape downtown Boston with state-of-the-art, energy-efficient residences. Through C-PACE's accretive financing structure, Millennium Partners was able to recapitalize this project post-completion with secure long-term, low-cost, fixed-rate capital, effectively injecting liquidity back into the property."

"For more than three decades, Millennium Partners has been committed to creating transformative developments that redefine urban living while delivering long-term value for our communities," said Millennium Partners Founder Christopher M. Jeffries. "Winthrop Center is a reflection of that commitment, and this financing through the PACE Massachusetts program recognizes the investments we have made in energy efficiency while providing long-term capital that supports the building's enduring performance. We are proud to partner with MassDevelopment and Nuveen Green Capital on a transaction that demonstrates how innovative financing can help advance the future of sustainable development."

Offering more flexibility than a direct loan, PACE Massachusetts allows property owners to undertake comprehensive energy upgrades without adding new debt to their balance sheet and through longer financing terms of up to 20 years. Projects eligible for financing include building-related energy systems such as solar panels, heat pumps, geothermal, energy-efficient lighting, and insulation. Massachusetts cities and towns are required to opt into PACE Massachusetts by a majority vote of the city or town council or the board of selectmen, as appropriate, in order for a property within that municipality to be eligible for the program. Eighty-nine cities and towns, including Boston, have opted in.

In June 2026, MassDevelopment, in partnership with DOER, advanced an updated, streamlined set of PACE Massachusetts guidelines for new construction properties to improve program usability, transparency, and market adoption. The modified guidelines set PACE Massachusetts financing levels for new construction projects based on the project’s compliance with the local building codes, thereby aligning financing amounts with each building energy code to determine PACE Massachusetts eligibility, expanding eligibility for allowable costs, and streamlining application and approval processes and requirements.

Located at 115 Federal St. in downtown Boston, The Millennium Residences are part of Winthrop Center, a 62-story mixed-use development by Millennium Partners that has become a global benchmark for sustainable urban design. The world's largest Passive House-certified office building, the development includes 317 luxury condominium residences, approximately 800,000 square feet of office space, below-grade parking and The Connector, a multi-level public gathering space serving residents, workers, and visitors. Winthrop Center has earned LEED Platinum and WELL Gold certifications, reflecting its leadership in energy performance, occupant wellness, and sustainable development.

MassDevelopment, the state’s development finance agency and land bank, delivers financing solutions, real estate expertise, and other assistance to strengthen and grow the Massachusetts economy. We partner with businesses, nonprofits, developers, banks, and municipalities, providing resources to help create jobs, build housing, and foster vibrant communities across the state. During FY2025, MassDevelopment financed or managed 409 projects generating investment of more than $4.65 billion in the Massachusetts economy. These projects are estimated to create or support 25,246 jobs and build or preserve 2,867 housing units.

About Millennium Partners
Founded in 1991, Millennium Partners is an internationally recognized developer of luxury mixed-use properties, responsible for landmark developments in some of the nation’s most dynamic urban locations. The firm has created an unparalleled portfolio of properties that bring together luxury condominiums, state-of-the-art entertainment complexes, world-class spa and fitness facilities, Class-A office space, and five-star hotel brands, including The Ritz-Carlton Hotel Company LLC and Four Seasons Hotels and Resort.

In Boston, Millennium Partners has been instrumental in shaping Downtown through projects including the record-setting Millennium Tower and Millennium Place, and most recently, Winthrop Center. Financed by Cale Street Partners, Winthrop Center is a next-generation mixed-use tower and the world’s largest Passive House-certified office building, designed with a focus on sustainability and workplace wellness. Together, these projects reflect Millennium Partners' continued commitment to thoughtful development and long-term investment in the city. For more information, please visit millenniumptrs.com.

About Nuveen Green Capital
With over $6 billion originated, Nuveen Green Capital is a national leader in sustainable commercial real estate financing solutions and an affiliate of Nuveen, the $1 trillion+  asset manager and wholly owned subsidiary of TIAA. The company, which was founded by C-PACE industry pioneers who helped design the nation's first successful statewide C-PACE program , has grown to offer a market-leading suite of accretive CRE financing products and a full-service lending platform with all underwriting, legal, and asset management functions executed in-house. To learn more, visit: Nuveen.com/greencapital

¹ Total assets under management (AUM) as of 1/1/2025

² The United States Department of Energy: 2016 C-PACE Report lists the Connecticut C-PACE program as the first statewide C-PACE program in the U.S.