Cool roofs have similar installation and maintenance costs astraditional roofs, and effectively reduce rooftop temperatures inhot climates. However, they can increase energy costs in colderclimates due to their decreased heat absorption capacity and must be combinedwith added insulation to keep buildings warm during the winter Green roofs have multiple benefits, makingthem an attractive solution for many issues facing urban areas.Similarly to cool roofs, green roofs can significantly reduce theUHI effect due to increasedreflectivity. In addition to reducing ambient air temperaturesin hot climates, the soil and vegetation layers of green roofsprovide natural insulation that mitigates short-term fluctuationsin air temperature This natural insula-tion leads to reduced building cooling requirements during thesummer and reduced heating during the winter Finally, rooftop vegetation can increase biodiversity improve air quality through leaf carbon uptake, and reducestormwater runoff . Plant species are typicallychosen to be drought resistant and have shallow taproots, and include sedums, other succulents andlocal native species . A potential disadvantage of green roofs is themoisture requirement for plant species during dry periods. Wateravailability dictates soil moisture and vegetation health, whichboth impact the cooling or insulating properties of the rooftop. Depending on plant species, soil depth, and water retentiveproperties, a green roof might require added maintenance andirrigation during drought periods.