Regarding the importance of a balanced interplay between the different aspects related to housing architecture in improving Urban Heat Island (UHI) and housing energy efficiency, this study aims at studying the interrelationships among these aspects in impacting UHI and housing energy consumption in small-scale apartment buildings of Mashhad, Iran.
The building industry has a significant impact on the UHI and energy consumption. This is especially critical in residential buildings. Balanced interrelationships among the different aspects related to housing architecture, i.e. building, environment and human, are crucial for reducing energy consumption and heat generation in the sector. However, this issue has not yet been thoroughly addressed in previous studies, particularly in Mashhad, Iran, where the majority of residential buildings are small-scale multi-story apartments. This study conducted Scatter Plot analysis technique on a database of 57 variables encompassing building, environmental and human characteristics, to assess their impact on environmental heat and energy intensity in small-scale apartments in Mashhad. The analysis, conducted via 228 bivariate linear correlations, classifying the influence of these variables into four impact levels – strongly positive, positive, negative and strongly negative – based on the slope of the Scatter Plot trend lines. The data were gathered from 20 buildings, 103 residential units and 227 people, through field observation, surveys, satellite-based measurements and software simulations.
The results indicate the correlations between the different aspects related to housing architecture (i.e. building properties (e.g. density, floor count), environmental factors (e.g. solar radiation, vegetation), occupants' sociodemographic characteristics (e.g. age, income, education) and environmental heat and energy intensity trends. Given the findings, the overall positive or negative impacts of the variables can be classified into two different areas. Accordingly, the variable trends that reduce the Environment Heat (EH) in both hot and cold seasons and cooling load in the hot season are set as variables with positive impacts, even though they may increase the heating load in the cold season, and vice versa. The main reason of this classification is the significance of the reduction of EH in both hot and cold seasons, and electricity consumption resulting from the decrease in the cooling load of the units in the hot season. However, this reduction may increase natural gas (CH4) consumption due to the growth in the heating load in the cold season. The findings in particular emphasized the especial role of occupants' sociodemographic characteristics, including gender, age, income and education levels in impacting environmental heat and energy intensity, demonstrating complex interrelationships between human factors and architectural factors (i.e. building and environment).
This study provides a suitable platform for a user-centered multi-criteria assessment of housing sustainability in small-scale apartment housing, which can help in an integrated decision making about the impacts of various aspects related to housing architecture, on heat generation and energy consumption, based on occupants' sociodemographic characteristics.
