Seattle’s iconic Spheres save 400 tons of CO2 with ECOPlanet


Decarbonizing construction, the Spheres building in Seattle is LEED Gold certified, with a live rainforest and built with ECOPlanet, with 80% less CO2 inside.

The challenge


The Spheres were developed to be the most unique workspace in the northwest of the USA and preserve the employees’ innate connection to nature. With an area of more than 6,200 square meters, the three spheres occupy only a small part of the major office complex headquarters but they are the focal point of the project, which was on track for LEED Gold certification.

The solution


At Holcim, we are leading the way to a net-zero future. With ECOPlanet – our global range of green cements – we enable low-carbon construction and create more liveable cities. ECOPlanet green cements start with a 30% lower footprint and can go all the way to 95% carbon reduction, and are fully aligned with the highest levels of sustainable building certifications. Holcim US worked closely with the client Stoneway Concrete to produce an ECOPlanet solution to help the Spheres achieve its goal of being a LEED Gold certified project.

"It’s our desire to create innovative solutions to solve problems and to protect our environment. We know through our own measurements that we’ve reduced CO2 by over 90,000 tons over the last ten years using ECOPlanet cement and similar products."

Greg McKinnon| OPERATIONS MANAGER, STONEWAY CONCRETE

The result


Thanks to the ECOPlanet solution, the project delivered more than 80% CO2 reduction over the industry average, saving up to 400 tons of CO2 and getting a LEED Gold certification. The Spheres span over three blocks in the center of the city. The intersecting spherical domes range from 24 to 29 meters in height, each taking up half of a city block. This greenhouse-like environment has been conceived to provide an inspirational space where occupants can live and work while surrounded by 40,000 plants from the cloud forests of 30 countries.