Identification and Prioritization of Quality Indicators for Building Facade Design; Using a Fuzzy Approach

Since 2013, with the formation of facade committees in Iran municipalities, and the start of reviewing designed facades in the process of issuing permits, the quality of building facades have been taken into consideration. However, facade qualitative aspects and its indicators (which have always been a point of disagreement among experts) are the most important challenges of this committee. Talking about qualitative issues and criticizing and analyzing the quality of a phenomenon has complexity and ambiguity, and the quality of the facade is no exception to this rule. Especially regarding the quality of facade design, aesthetic and sensory issues make evaluation and criticism more difficult. This has made the facade evaluation meetings difficult in the municipal committees. It appears that conducting research to determine the quality indicators and dimensions of facade design, as well as identifying issues of criticism and evaluation of building facades, would be necessary in order to clarify the topics discussed in facade committees. This article’s objective is to address the aforementioned challenge by identifying quality indicators associated with building facade design and prioritizing them through the lens of professionals in architecture and urban planning. In order to clarify the goal and the research questions, the current research is focused on mid-rise residential buildings in the city of Tehran.

This research approach is to deal with the issue of quality in building façade design comprehensively and without prejudice. In this regard, firstly, in order to identify quality indicators in architectural design, reliable scientific sources have been studied, and as a result of this study, 22 quality indicators related to facade design have been identified by interviewing and consulting with experts and specialists. The indicators related to building façade design are divided into three main aspects: functionality, persistence, and impact. They are further classified into seven subgroups. In the next step, in order to prioritize the indicators, a questionnaire with a Likert scale and fuzzy numbers was given to the design supervisors in architectural and urban planning consulting offices in Tehran. The population for this study consists of 182 members. A total of 132 questionnaires were distributed for data collection, and 126 completed questionnaires were received. 

According to the survey responses, safety, privacy, lighting, and durability were identified as the most important quality indicators for building facades from the perspective of experts and specialists. On the other hand, flexibility and adaptability, continuity and integration, and enclosure were found to be the least important factors. “The “Safety indicator” refers to the measures taken to ensure the safety of the building and its occupants. This includes features such as protection of the edge of platforms, restricting access for unauthorized persons, and ensuring that the walls, doors, and windows are strong enough to prevent unauthorized entry. The “Privacy indicator” pertains to the importance of maintaining the privacy of spaces and allowing for social monitoring through the use of appropriate openings, while the “Lighting indicator” focuses on having enough openings and depth of light penetration to make use of natural light, providing enough light to display facade and volume of the building at night and lighting up the urban space adjacent to the façade. According to the findings, the experts gave the most importance to the subgroups related to comfort, building engineering systems, and environment in building façade design. These subgroups were identified as containing the most significant indicators by the experts. Also, from the expert point of view, the durability aspect, then the functionality aspect, and then the impact aspect are considered the most important building façade design quality indicators. In addition, experts consider durability and pollution, and waste production as the most important indicators of the persistence aspect; safety and lighting as the most important indicators of the functionality aspect; and privacy and identity as the most important indicators of the impact aspect.

In a general view, according to the surveyed population of this study, performance and durability are considered more significant than urban aesthetics and impact-related matters. Impact aspect indicators play a very important role in the formation of urban image and identity, and it is necessary for designers and specialists to pay more attention to these factors. Also, according to the results, it can be concluded that the designers’ focus is often on the project as an isolated building, and it is necessary to pay more attention to the relationship between the building and its neighbors, alleys, and streets, and finally the neighborhood and the city.