Building a Sustainable Future: Energy Benefits of Native Grass Green Roofs
Start Date
23-4-2025 4:15 PM
Location
2nd floor - Library
Abstract
Urbanization results in pressing economic and environmental issues related to energy use, the urban heat island effect, and stormwater. Green roofs have emerged as a sustainable urban design concept to combat these economic and environmental problems, but little research has investigated the effects of native plants on the energy and water storage related benefits of green roofs. This study evaluated the effects of native grasses and forbs and their management on green roof thermal dynamics. To evaluate these effects, we monitored 28 green roof plots consisting of seven different treatments, including (1) native grasses with no management, native grasses accompanied by aboveground dead grass removal in the (2) fall or (3) spring, (4) native grasses and forbs with no management, native forb and grass treatments accompanied by aboveground dead plant material removal in the (5) fall or (6) spring, and (7) unplanted plots. Each plot was monitored using temperature and moisture probes that collected measurements every 5 and 15 minutes, respectively. Early results beginning in October 2024 and running through January 2025 indicate that green roofs planted with native grasses can increase roof surface temperature by at least 2 degrees Celsius. However, these benefits appear to result from the insulative properties of the green roof soil, with additional thermal benefits expected during the growing season due to evaporative cooling from plant transpiration. The insulative benefits observed thus far suggest the addition of grass-based green roofs on new and existing buildings could help urban areas transition towards a more sustainable future.
Building a Sustainable Future: Energy Benefits of Native Grass Green Roofs
2nd floor - Library
Urbanization results in pressing economic and environmental issues related to energy use, the urban heat island effect, and stormwater. Green roofs have emerged as a sustainable urban design concept to combat these economic and environmental problems, but little research has investigated the effects of native plants on the energy and water storage related benefits of green roofs. This study evaluated the effects of native grasses and forbs and their management on green roof thermal dynamics. To evaluate these effects, we monitored 28 green roof plots consisting of seven different treatments, including (1) native grasses with no management, native grasses accompanied by aboveground dead grass removal in the (2) fall or (3) spring, (4) native grasses and forbs with no management, native forb and grass treatments accompanied by aboveground dead plant material removal in the (5) fall or (6) spring, and (7) unplanted plots. Each plot was monitored using temperature and moisture probes that collected measurements every 5 and 15 minutes, respectively. Early results beginning in October 2024 and running through January 2025 indicate that green roofs planted with native grasses can increase roof surface temperature by at least 2 degrees Celsius. However, these benefits appear to result from the insulative properties of the green roof soil, with additional thermal benefits expected during the growing season due to evaporative cooling from plant transpiration. The insulative benefits observed thus far suggest the addition of grass-based green roofs on new and existing buildings could help urban areas transition towards a more sustainable future.
