Energy-Efficient Solutions Depending on Building Forms Design with Tilted South and North Facades

Abstract

Interactions between buildings and outdoor environment variables, such as the sun, wind and precipitation, depend on building parameters such as orientation, colours, materials and forms. Building forms are one of the most important parameters that directly impact the cooling and heating load energy consumption, daylight environment and urban sustainability. The current study focused on how building forms affect the energy performance of buildings. Inclined forms that were shaped based on the inclination of south and north facades were studied. Many methods were used to explore the impacts of several variables, including exposure to direct sunrays and heating and cooling load. Thermal performance and energy consumption were investigated for many inward- and outward-tilted angles forms for both the south and north directions and compared to vertical facades. In addition, the study developed new building forms based on a combination of south and north tilted forms, which have low energy consumption. The configurations achieved an acceptable balance between cooling and heating energy consumption. A series of computer simulations were developed using energy plus a calculation engine within DesignBuilder, SunCast, Radiance and IES VE. The results showed that outward-tilted facades for the south orientation perform well, as they reduced the cooling load due to self-shading. Building forms that balanced south and north tilted facades saved the most energy. South-tilted facades forming only 30° angles performed the best, with average energy savings of 20%. Meanwhile, forms with 30° south-tilted facade and 10° tilted north facades, such as forms 3–6, reduced energy consumption by more than 23% compared to the base case.