City of Reno: Mitigating the urban heat island effect with green roof systems

Project Title

Green Roof Technical Briefing

Research Question

This proposal is to address barriers and create tools and resources to advance one of the recommended strategies for mitigating Urban Heat Island – green/vegetated roof systems.


The City of Reno is already experiencing a changing climate, and among the changes is an increase in heat extremes. In 2017, the city partnered with the University of Nevada, Reno to assess local trends in extreme urban heat, local impacts of the urban heat island effect (UHI), impacts to vulnerable populations, and strategies to mitigate UHI. In acknowledgment of the impacts of UHI, the city also incorporated a policy in its updated Master Plan to mitigate the UHI effect.

Additionally, the Washoe County Health District’s Air Quality Management Division (AQMD) partnered with Arizona State University to utilize NASA Earth observations to assess the UHI and specific factors related to UHI, including urban tree canopy cover, rooftop albedo, impervious surfaces, and exposure to vulnerable populations. AQMD participates in the U.S. Environmental Protection Agency’s Ozone Advance Program, a voluntary program to promote local initiatives for reducing fine particulate and/or ozone pollution. The UHI effect contributes to an increase in ground-level ozone. The goal of AQMD’s project was to utilize tools that can inform decision-making toward decreasing the amount of the region’s hardscaped, impermeable, and heat absorbing surfaces to reduce the UHI and ground-level ozone.

Reno is growing hotter more quickly than any city in the U.S. The average annual temperature rose more than 7 degrees Fahrenheit over the past 50 years. In 2018, Reno experienced the hottest summer on record and the highest number of 100 plus degree Fahrenheit days. The 10 hottest summers on record occurred over the past 15 years.

The Reno area is impacted by the UHI effect and a reduction in nighttime cooling. Research shows that extreme heat days and nights have increased in magnitude and frequency. Extreme heat events during summer represent a major public health impact, especially for vulnerable populations such as low-income, children under five, elderly, and residents with lung and coronary diseases. With more extreme heat during both days and nights, the health impacts of affected populations are exacerbated because individuals are unable to recover from daytime heat stress. Through this project, the researcher will utilize available data gathered through the projects referenced above to raise awareness and educated decision-makers and the community about the localized data on UHI, day and night extreme heat, and projections for increases in UHI. The researcher will also present the impacts of UHI on Reno and vulnerable populations, and areas with high UHI Vulnerability Index. The outcomes of the activities to be conducted under this proposal will be to remove barriers to implementing known solutions for reducing UHI by providing the information and analysis needed to support decision-making, and integrate best practices into procurement, policies, codes and regulations.


Research green/vegetated roof systems, analyze cost/benefits, and recommend specifications, policy options and proposed amendments to codes or design standards. Develop a technical briefing on green/vegetated roof systems.

Suggested Skills

Understanding of design and engineering. Ability to conduct cost assessments. Proficiency in technical writing. Experience research codes and regulations. Possible fields of study include Engineering, Natural Resources and Environmental Science.

Agency Representative

Lynne Barker
(775) 334-2288