Paper Title
Impact Of Plant Height And Irrigation On Thermal Performance Of Extensive Green Roofs In Riyadh City

Abstract
Increasing worldwide environmental concerns (Global warming, depletion of natural resources, acidrains, air and water pollutions, and ozone depletions) have led to the development of environmentally friendly construction practices. Green roof is one of the sustainable practices for reducing the environmental impact of a building. The study aim was identifying the impact of plant height and irrigation on thermal performance of an extensive green roof system in Riyadh city influenced by tropical and harsh climate.The experimental validations were applied on residential building in Riyadh city during the summer season in 2014. The experimental validations results indicated that the tall grass with average height from 6 to 15cm can reduce the temperature of internal air from 0.5 to 1C, in comparison to the short grass with average height from 3 to 6 cm in similar conditions. While, the temperature of internal air differences were of 0.00.5C with regular irrigation or irregular irrigation. However, when irrigation stopped more than two days, the grass would wither. Finally, this study has demonstrated that the grass height was more effective for its impact on the thermal performance than regular or irregular irrigation. Keywords- Internal Temperatures,Irrigation,ShortGrass, Tall Grass, Thermal Performance.