Energy efficiency design guide for optimal urban features of open spaces in residential complexes

The energy consumption in buildings and especially residential buildings is immensely affected by the design of urban open spaces around these buildings. Many countries including Egypt have been witnessing rapid growth in residential complexes while the effect of urban design on microclimate and energy use is not given appropriate considerations. Accordingly, this has contributed to the massive increase of energy consumption. Many studies have been conducted for analyzing the effects of urban features of open spaces (variables) and their values on the microclimate. A set of values for one or more variables were addressed in each of these studies and their effect on urban microclimate and energy use were measured. However, such effects were diverse and dispersed. Therefore, the aim of this paper is to identify the optimal settings of urban features of open spaces that contribute to reducing energy consumption in buildings and achieve outdoor thermal comfort in the context of urban open spaces in residential complexes. In order to achieve this goal an extensive and thorough literature review is conducted for classifying and analyzing the impacts of different values of each urban feature of open spaces on energy use and thermal comfort. The urban features of open spaces in residential complexes are classified into five categories: urban morphology, street pattern, urban density, building distribution, and urban canyon. There are various subvariables for each category with corresponding range of values which are classified into different sets. Each set corresponds to the same urban pattern and climate zone. The results of these sets and categories are comparatively analyzed in order to identify the optimal values that contribute to reducing energy consumption in buildings and achieve outdoor thermal comfort. The outcome of this extensive comparative analysis is resulted in the form of five main urban patterns (that are dominantly used in residential complexes), for the two climate zones in Egypt (hot arid, and hot humid) along with the optimal urban design features of these five main urban patterns. The outcome of this research paper is presented in a matrix format that graphically presents these urban patterns and the optimal values of the urban open space features (variables) along with the indicators of energy consumption and outdoor thermal comfort. This matrix provides architects and building designers with a useful and friendly design guide that can be used at the early phases of urban design and can help them to achieve energy efficient and comfortable urban-open spaces in residential complexes. Such design guide will contribute in improving the awareness of designers at the early phases of the design process and direct their designs to be energy conscious and efficient prior to the detailed design phase wherein energy simulation is time-consuming and expensive.