Investigation of Greening Façade and Retrofitting Strategies on Outdoor Thermal Comfort and Indoor Energy Consumption in New Assiut City, Egypt

Abstract

This study aims to investigate the effect of greening façades and roofs on the outdoor thermal comfort of residences and indoor energy consumption within the context of different retrofitting strategies. The proposed methodology con-sists of two main stages, first Envi-met will be used to model the base case and study the effect of green walls and roofs on outdoor thermal comfort, then DesignBuilder will be used to estimate the annual energy consumption of the base case and six retrofitting strategies. An investigation was performed for a new residential complex Youth housing sector in New Assiut City as a model of public low-income housing in many Egyptian desert cities. The results concluded that a significant reduction in Physiological Equivalent Temperature (PET) is achieved in the canyon between buildings using green walls, a reduction that ranged between 4.20°C and 11.20°C. Furthermore, the integration of green walls with different retrofitting strategies (wall and roof insulation and replacing lamps with light emitting diode (LED) units) achieved a further reduction in energy consumption that reached 32.67% in the weather file of 2020. Additionally, the usage of green walls and roofs in the case study is considered an appropriate strategy for the residential existing buildings, besides its durability, low economic required compared with other strategies such as adding concrete shading, its role in preserving the environment, ease of implementation by the residents, and applicability in different Egyptian desert cities. Finally, the findings generate wider benefits for a residential community of low-income people.