A landmark green roof for USCG HQ

Green roofs at scale 

At 400,000 sq. ft., the Coast Guard HQ green roof is the second largest in the nation. Installed with Sempergreen Sedum blankets, it immediately offered a dense 95% plant coverage. That stability means no loose substrate blowing away, no patchy establishment phase, and far less maintenance. The mix of Sedum species is resilient in Washington’s climate, withstanding both summer heat and winter frost. Beyond aesthetics, the green roofs play a crucial technical role: they absorb rainfall, slow down runoff and channel excess water into the site’s stormwater pond for reuse in irrigation. 

Design rooted in ecology 

The landscape architects designed each courtyard and roof as a living reference to one of five regional eco-zones, from Piedmont uplands to coastal plains. This ecological storytelling creates varied habitats for pollinators and birds while giving staff and visitors a restorative environment. The design philosophy, bringing nature back into a highly secure campus, aligns with DHS’s vision for resilience and sustainability. 

Award-winning sustainability 

When the project began, federal guidelines required LEED Silver certification. Midway through, the target was raised to Gold. Despite the challenge, the Coast Guard HQ achieved LEED Gold, thanks in large part to its extensive green roofs and water-saving design. The building has since received more than 16 awards, including recognition from the Chicago AIA and the Washington Building Congress. The project is now seen as a benchmark for large-scale sustainable government facilities, balancing operational security with ecological value. 

A resilient investment 

Green roofs don’t just enhance wellbeing and ecology, they also extend roof life. Protected from UV radiation and heavy rain, the underlying membrane lasts up to three times longer. For a federal building of this scale, that translates into significant long-term savings and reduced material use. With the Sempergreen system, the Coast Guard HQ has a roof that is as future-proof as the mission of the organisation itself. 

Setting a federal standard 

The Coast Guard Headquarters didn’t just create a healthier, more efficient workplace for its 4,000 employees, it set a precedent. By proving that even one of the largest federal campuses could embrace living architecture, the project raised the bar for government buildings across the country. Its combination of security, sustainability and design excellence has become a reference point for new DHS facilities and beyond. With its sweeping green roofs, the headquarters demonstrates that ecological responsibility is not an optional add-on, but an integral part of building for the future.