B39ES is a design collective interested in the climate, energy, and material systems of our rapidly changing world. Founded in 2025 by Cat Chen and Connor Gravelle and based in New York City, we see architecture as a medium for imagining ways of life that are both ecologically reciprocal and socially just. We're not a traditional office but a porous collective. We operate differently. We grow, adapt, and take shape around each project, whether that's social cooling devices, environmentally entangled performance infrastructures, or low-energy housing.
Who we are
Cat Chen is an architectural designer, researcher, and educator and the 2026-27 Steedman Fellow. She holds an M.Arch from the Harvard Graduate School of Design and a B.A. in Studio Art and Physics from Colgate University. Cat has taught at Harvard and Cornell and practiced in offices in Zürich, Boston, Princeton, and New York.
@_cat_chen
Connor Gravelle is a licensed architect and educator based in New York City with experience at offices in Los Angeles, London, Seoul and New York. He holds an M.Arch from the Harvard Graduate School of Design and a B.Arch from the Southern California Institute of Architecture. Connor’s work focuses on how questions of land, labor, and ecology entangle architecture in worlds beyond itself.
@connorgravelle
Let's chat
b39es.studio@gmail.com
News
260701
Connor presents at the 2026 UIA World Congress of Architects in Barcelona on the panel "Economy of Means", moderated by Andrea Arriola Fiol alongside Alonso Atienza and Trung Mai.  
260508
Cat is named the 2026 James Harrison Steedman Memorial Fellow at WashU Sam Fox School of Design & Visual Arts. Her proposal,  Solar Communities: Architectures of the Energy Transition, will see her study emerging energy communities in Spain, Germany, and Japan.
260320
The Design Trust for Public Space selects B39ES as a semi-finalist for its 2026 RFP incubator program, organized around the theme of water. Our proposal, Public (In)Decency, proposes to evaluate the history and spatial constraints of New York City's public toilets with an emphasis on developing passive and sustainable strategies for expanding access and sanitary equity.
260219
Concéntrico names B39ES's proposal, Lavadero Pequeño, as a finalist for the "Urban Ecologies" programming of its 2026 festival.
250821
Cat and Connor join Cornell University College of Architecture, Art, and Planning (AAP) to teach 1st- and 2nd-year BArch studios, seminars and graduate/undergraduate thesis.
250528
Connor is awarded the James Templeton Kelley Prize at Harvard GSD for his graduate thesis, The Only Way Out is Through: Architecture, Building, and Our Entangled Present in Gary, Indiana, advised by Eric Höweler. The prize, awarded to one student from each of the school's architecture programs, recognizes the top final design project in a graduating class.
250528
Connor receives the Gerald M. McCue Medal in recognition of achieving the highest overall academic record of a student graduating from a post-professional program at Harvard GSD.
250528
Cat is awarded the Alpha Rho Chi Medal at Harvard Graduate School of Design (GSD) in recognition of her record of leadership and service during her graduate degree.