Salesforce Park Transit Center - San Francisco
Created the world's largest ecosystem rooftop, transforming urban biodiversity in downtown San Francisco.
Except researched and created the concept for what became the largest ecosystem rooftop in the world, working with architecture office Pelli Clarke & Partners. Salesforce Park and Transit Center in San Francisco stands as a global example of how we can transition city biodiversity, health, and sustainability through bold architectural intervention.
The project emerged from a global design competition for the redevelopment of the Transbay Transit Center. On September 20th, 2007, our rooftop park concept won against entries from around the world. Our research revealed downtown San Francisco's SoMa district was heavily concreted and asphalted, in dire need of solutions for the heat island effect, biodiversity, climate-adaptive rainwater management, and places for people to connect outdoors.
The Problem
San Francisco's downtown core suffered from extreme urban heat, minimal biodiversity, and a complete lack of green public space. The historic 1939 Transbay Terminal needed replacement, but simply building a new transit hub would miss the opportunity to address the district's environmental challenges. The design had to reconcile major transit infrastructure with the ecological needs of a dense urban center.
The challenge was to create a living ecosystem atop one of the world's busiest transit terminals, one that could cool the area, capture and store rainwater, boost ecological diversity, and provide a vital gathering place, all while meeting the structural and safety demands of a major transportation facility.
Process
Ecosystem services research
We conducted extensive research into the area's environmental needs, mapping heat islands, biodiversity gaps, and stormwater challenges. This informed a concept built around ecosystem services: cooling, water capture, biodiversity, and social connection as integrated design drivers.Integrated rooftop ecosystem design
The design places a complete living ecosystem atop the transit terminal. Native and adapted plant communities create microclimates, capture rainwater, support pollinators, and reduce ambient temperatures for the surrounding blocks. Every species was selected for its contribution to the broader system.Competition-winning concept
Together with Pelli Clarke & Partners, the concept was refined through an iterative process balancing ecological ambition with structural feasibility. The result won one of the largest architectural competitions ever held, earning the right to transform a critical piece of San Francisco's infrastructure.Outcomes
- Park area
- 2.2 hectares
- World's largest ecosystem rooftop park
- Plant species
- 600+
- Native and adapted species supporting urban biodiversity
- Daily visitors
- 10,000+
- Public green space serving downtown workers and residents
- Temperature reduction
- Significant
- Measurable cooling of surrounding urban heat island
Gallery
