A Building Designed to Grow Sustainably
The Millennium Building, located at 1909 K Street NW, has a decades-long history of staying ahead of the sustainability curve. Originally constructed in the 1960s and limited to nine floors by a height restriction, the building was designed with a forward-looking touch: Tower Companies founder Albert Abramson had the structural columns built to support additional floors, anticipating a future expansion. That foresight paid off in 1999, when the newly renamed Millennium Building added three floors in a major renovation. It do so without increasing the building’s overall energy consumption. In the 27 years since, the building has continued to set the standard for sustainable office space in DC.
Solar Power and a Renovated Rooftop Experience
That momentum has continued in recent years. In 2025, Tower Companies installed a 125 kW solar array at the property, which has already generated more than 200 megawatt hours of power. The array is now prominently featured on the building’s renovated penthouse level, giving clients and visitors a visible look at renewable energy production in action. In 2026, the building also opened a renovated roof deck and conference center space, incorporating high-efficiency HVAC equipment, curtainwall, sustainable flooring, and thoughtful landscaping to elevate the client experience.
Together, these upgrades build on a long-term efficiency strategy: from 2010 to 2025, Tower Companies reduced energy use at the property by approximately 50% through equipment replacements, green leasing practices, sustainable tenant build-outs, and ongoing operational improvements.
Luke Lanciano, Senior Director of Sustainability at The Tower Companies, said the certification reflects the depth of that work:
“The Green Globes certification process is an excellent way to holistically evaluate a building’s performance across a range of categories. We are pleased to have partnered with GBI for this certification, and proud to be the first 3 Globes certified office building in DC under their latest Existing Building protocol.”
The Value of Third-Party Assessment
Tower Companies also credited the certification process itself, and GBI Assessor Buddy Humphries in particular, with sharpening the project’s outcomes. As Lanciano explained:
“It’s always valuable to have a third-party review the building from top-to-bottom to help provide perspective on how our initiatives, practices, and standard operating procedures compare to the market, so Buddy was a big help offering his expertise and helping ensure the building was meeting or exceeding standards across the range of Green Globes categories.”
Project Team
- Donna Nurmi, DC Commercial Portfolio Manager
- Tia Carson, Property Manager
- Mike Newman, Chief Engineer
- Harold Green, Maintenance Technician
- Vinh Nguyen, Maintenance Technician
- Luke Lanciano, Director of Sustainability
Looking Ahead
With this certification, The Tower Companies continues to push the boundaries of what’s possible for sustainable, high-performing office buildings and aims to set the pace for sustainable office space across the DC market. The Millennium Building’s combination of long-term efficiency gains, renewable energy investment, and holistic third-party evaluation make it a model for what a decades-old office building can achieve.
Leasing inquiries: Randy Harrell, Executive Vice President, CBRE — (202) 585-5556, randy.harrell@cbre.com
