Cooling the Plaza

This report was prepared by graduate students in the Urban Heat Analytics course in the Department of Urban Policy and Planning at Hunter College, City University ofNewYork, during the Spring 2026 semester. The course was taught by Mehdi Heris.As part of the course, students examined the regulatory planning framework governing New York City’s Privately Owned Public Spaces (POPS) program and applied urban climate science, geospatial analysis, and microclimate modeling techniques to evaluate the thermal performance of publicly accessible open spaces.

The project explored how planning, design, and regulatory strategies can improve thermal comfort and strengthen heat resilience in NewYork City’s public spaces. performance of publicly accessibleopen spaces in NewYork City, and explore planning and design strategies to improveheat resilience. The project was developed in collaboration with the New York City Department of City Planning (NYC DCP). We are grateful to Emily Sun and the division of Climate & Sustainability Planning of DCP, who proposed the project and provided guidance, feedback, and technical insights throughout the semester. Their engagement with the class helped connect academic analysis to real-world planning challenges and enriched the students’ learning experience.

This report evaluates the thermal and microclimatic performance of three publicly accessible plazas in New York City to inform zoning recommendations for the Privately Owned Public Space (POPs) program. Our findings illustrate how targeted regulations play a central role in shaping urban microclimates and addressing rising heat exposure in public spaces. Across the three case studies, trees and shade structures reduced ambient temperatures in adjacent areas by approximately 2°F to 9°F (1°C to 5°C), demonstrating the measurable cooling benefits of climate-responsive design interventions. As New York City continues to expand publicly accessible open spaces through the POPS program, climate warming must be treated as a core planning concern rather than a secondary design issue. This is especially the case in high-heat-vulnerability neighborhoods. This requires revisiting the City’s zoning and regulatory framework to ensure that future plazas are designed not only for accessibility and aesthetics, but also for heat resilience and long-term public comfort. Because zoning fundamentally shapes the form and performance of buildings and open spaces, it should be updated to explicitly incorporate thermal comfort and climate adaptation objectives.

Drawing on performance-based models from Cambridge, MA, and seasonal comfort designs of Iranian Hayats, we offer six specific recommendations for POPS zoning changes: (1) a shading minimum with a reference moment (July 15 at noon), (2) seasonal design requirements allowing winter sun and summer shade, (3) frontage and glazing standards that mitigate reflected heat, (4) light-colored, permeable, and thin paving materials, (5) a performance-based zoning framework with FAR bonuses tied to cooling outcomes, and (6) tree canopy standards based on Leaf Area Index and crown width rather than simply tree counts, supported by centralized governance and maintenance coordination. Integrating these interventions into the POPs program would help every new plaza contribute meaningfully to a citywide, equitable heat mitigation strategy.

Read the full report here: Urban-Heat-and-POPS