Call for Product Samples: Green Roof Performance Testing

Green roof at New School, Parson School of Design, August 8 2024. Photo by NYCEP

Please note: Participants must contact Grace Hiestand at ghiestand@auroran.net by March 27, 2026 to confirm their interest. Samples should be delivered to the testing facility in Spring 2026.

Download the Green Roof Performance Testing Brochure for additional details.

Background

The NYC Department of Environmental Protection (DEP), in partnership with Drexel University and with support from eDesign Dynamics, is launching a controlled field experiment to evaluate innovative green roof systems and how they compare to typical systems used in NYC. As the green roof market rapidly evolves, the City is working to ensure its regulations and incentives remain current and effective.

Innovative systems—such as storage-based, wick-driven, fleece-based, and hybrid blue-green roofs—may provide equal or better stormwater performance with less depth and/or lower weight, but currently lack standardized, field-based verification under real NYC climatic conditions. This research aims to:

• Increase the variety of approved green roof solutions for New York City buildings.
• Alleviate restrictions stemming from structural issues, costs, and supply chain disruptions.
• Promote the use of data and research to inform updates to design guidance and regulatory standards.

Experiment Setup

The figure to the right shows the layout of the weighing lysimeter testing facility.

The trial compares:

• 3 replicates: 4″ standard green roof
• 3 replicates: Your proprietary green roof system

Each system will undergo a two (2) week testing period, during which it will be monitored side by side with the standard green roof replicates under identical weather conditions, allowing for direct comparison of hydrologic performance.

Requested from Manufacturers

Participating manufacturers must provide, at no cost, materials for three (3) small-scale samples (1 m² each) of their proprietary green roof system, sized for individual lysimeter platforms.

What Manufacturers Receive

• ✔ Full access to raw and processed performance data for their system
• ✔ Direct comparison to 4″ standard green roof
• ✔ Evaluation under real-world NYC climate conditions

Visit Green Infrastructure to learn more about our programs. If you would like to learn about future stormwater events and initiatives, visit Newsletters and subscribe to the “DEP Stormwater” email list.