Team
We’re a hands-on partnership leading each project, ensuring continuity and accountability.
Founded in New York in 2019, OstrowHarding brings direct experience across cultural, commercial, and residential projects — from early concept through construction.
Our work is grounded in rigorous thinking, developed through close collaboration with clients, consultants, and fabricators — and built with advanced modeling tools.
We offer complete design services across residential, hospitality, commercial, and civic projects, with close attention to clarity, materials, cost, and buildability.
Harding Ostrow Architects, PLLC is licensed to practice architecture in New York State and is an NYC-certified Minority Woman-Owned Business Enterprise (M/WBE). The partners hold national NCARB certification.
Rosannah Harding, AIA, NCARB, ISHC, LEED AP BD+C
Rosannah Harding is a founding partner of OstrowHarding. At 23, she became the youngest architect admitted to the American Institute of Architects. She earned her B.Arch with High Distinction from California College of the Arts in 2007 at 18 years old and her M.Arch from The Cooper Union in 2014 with a concentration in Urban Studies. As a Project Architect at Diller Scofidio + Renfro, she spent six years on The Shed — DS+R’s telescoping performing arts center in New York — from early design through opening day. She later served as Studio Director at CAL Collaborative, Gabriel Calatrava’s multidisciplinary practice, leading projects across master planning, architecture, exhibition, and industrial design. Rosannah is a registered architect in both New York and California and teaches at Parsons. She works closely with clients throughout the design and construction process.
Matthew Ostrow, AIA, NCARB
Matthew Ostrow is a founding partner of OstrowHarding. He holds a professional degree in Architecture from The Cooper Union and brings over 25 years of experience. As an Associate Principal at Diller Scofidio + Renfro, Matt was a pivotal contributor to more than 40 major projects — including The Shed, The Broad, the Hirshhorn Bubble, Columbia University Medical School, and the Museum of Image and Sound in Rio de Janeiro. Matt has garnered over 15 design competition wins. His expertise in design, digital modeling and advanced fabrication coordination was central to the execution of these complex projects through construction. Matt is an adjunct professor at both Pratt Institute and Parsons, and lectures internationally. His work focuses on structure, and close collaboration with engineering and fabrication teams.
Prior Projects
The Shed
The Shed’s telescoping outer shell allows the building to expand and contract, creating flexible infrastructure for art, music, and public events. Our involvement focused on schematic design through opening day ensuring the ambitious design was executed with precision.Diller Scofidio + Renfro
Ostrow, Lead Designer
Harding, Designer
New York, NY
The Shed (Non-profit)
Museum / 200,000 SF
2019
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The Broad
The Broad museum is defined by its porous concrete facade, which filters natural daylight into the column free gallery space. Our involvement while with DS+R was from day one of the competition and focused on geometric control of the veil and advancing the project through detailed development and construction.Diller Scofidio + Renfro
Ostrow, Lead Designer
Los Angeles, CA
Eli Broad
Museum / 140,00 SF
2016
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