Introduction
Climatology plays a highly significant role in architectural studies. This importance has historically manifested itself in the design and formation of building volumes, the number and placement of openings and windows, and the configuration of solid and void spaces [Mahdavinejad et al., 2017]. Our predecessors, by applying climatic principles and considering cultural and religious conditions, designed buildings in a manner that ensured maximum protection and thermal comfort under diverse hot and cold climatic conditions [Mahdavinejad, 2004]. In many cities such as Isfahan, Yazd, Tabriz, and Bandar Abbas, there are clear examples of energy-efficient designs in historical buildings inherited from past generations [Amini et al., 2014; Kasraie et al., 2016; Mohtashami et al., 2016].
In recent decades, energy consumption and consequently challenges such as air pollution and the depletion of energy-producing resources has become one of the most critical issues facing contemporary architects and designers both globally and in Iran. Therefore, attention to climate and its impact on the modern building design process has become increasingly significant. Numerous studies in architectural research have emphasized climate consideration and climatic zoning as effective approaches to reducing and optimizing energy consumption. Accordingly, by taking building energy use into account, new climate-responsive architectural design techniques can be developed [Mahdavinejad et al., 2012]. Among these techniques, particular emphasis is placed on the utilization of natural airflow in various parts of buildings, especially within the building envelope, which serves as the primary and most crucial interface between interior spaces and the external environment. Through intelligent design of the building envelope, objectives such as reducing heating and cooling energy demand, maximizing the use of natural daylight, and achieving architectural lighting can be attained. In this regard, the Iranian government has also enacted regulations aimed at environmental protection and sustainability [Mahdavinejad et al., 2017].
In recent years, energy-related issues across Iran’s diverse climatic regions have gained greater importance due to the energy crisis and the increasing utilization of solar energy. Public awareness of climatic conditions in Iran, along with favorable climatic potential, widespread use of natural ventilation, and abundant solar radiation in most regions, can lead to high-capacity utilization of renewable and clean energy sources. Climate-responsive architectural design is feasible when climatic data and the thermal requirements of the construction site are available [Siadati et al., 2021]. In earlier studies, climatic patterns were predominantly defined in relation to macroclimatic conditions, and macroclimatic zoning for many regions and cities in Iran has either not been conducted or was carried out in the past. However, with advancements in related software such as ArcGIS and the development of new statistical methods, previously established climatic zonings may require revision [Nikghadam et al., 2016]. Climatic elements encompass a wide range of data; while not all of these parameters are applicable to climate-responsive architectural design, climatic zoning can nonetheless be performed based on selected parameters.
Moreover, certain technologies in various fields, including architectural design cannot be implemented uniformly across all cities due to differing cultural, political, and social parameters. For example, the double-skin façade, a type of building envelope that operates based on solar radiation and natural airflow and can significantly reduce building energy consumption, is most often applicable in high-rise office buildings and in cities with high building density. Therefore, identifying cities that both represent specific climatic conditions and possess the potential for implementing such building envelopes is of considerable importance.
Given the specialized nature of climatic zoning within the field of climatology, the most appropriate approach for determining the climatic types of Iran’s provinces is to rely on established climatological studies. In this regard, climatic zoning analyses can serve as valuable references for researchers in the field of climate-responsive architecture. The objective of this study was to conduct a content analysis of climate-responsive architectural studies with respect to the methodologies employed, the geographical regions examined, and the adequacy of climatic zoning data derived from climatological research
Methodology
This applied study was conducted in 2021 using a quantitative citation and content analysis approach. Data were collected through library-based research, review of written documents and records, and systematic searches of domestic academic journal indexes. Out of a total of 160 articles, 101 peer-reviewed research articles published between 2001 and 2020 in the field of architecture related to energy and climatology in Iran were selected for analysis. These articles were identified using the keywords “climate” and “climatic zoning.”
The research instrument consisted of a coding sheet developed based on expert opinions from scholars in the field of architecture. These expert insights were used to identify approaches to utilizing climatic zoning data and the types of climatic information applied in architectural studies. Based on the review of expert opinions, the factors most frequently employed in architectural research were identified and recorded as the main coding categories. Subsequently, the selected articles were systematically reviewed, and the types of climatic information used in each study were recorded according to the predefined categories in the coding sheet. Based on this coding framework, methods of using climatic data in architectural studies were classified into three categories: descriptive (quantitative, qualitative, and mixed quantitative–qualitative), quantitative, and field-based approaches. Climatic data were also classified into five categories, including precipitation, wind, temperature, humidity, solar radiation, and composite elements. Following final revisions, the coding framework was validated.
To assess reliability, Scott’s Pi coefficient was employed, yielding a reliability value of 0.89, which was considered acceptable. For article selection, domestic peer-reviewed journals specializing in architecture and urban studies were systematically reviewed. These journals included: (1) Bagh-e Nazar; (2) Soffeh (Shahid Beheshti University); (3) Urban Management (Urban and Rural Studies Research Center); (4) Iranian-Islamic City Studies (Academic Center for Education, Culture and Research); (5) Architecture and Urban Planning (formerly Honar-ha-ye Ziba), Faculty of Fine Arts, University of Tehran; (6) Arman-Shahr Architecture and Urban Planning; (7) Urban Identity (Islamic Azad University, Science and Research Branch); (8) Iranian Architecture and Restoration; (9) Housing and Rural Environment; (10) Iranian Architecture Studies; (11) Islamic Architecture Research; (12) Architectural Studies; (13) Iranian Architecture and Urbanism; (14) Journal of Architecture and Urbanism; (15) Naqsh-e Jahan; and (16) Architecture of Hot and Dry Climates.
In addition, a general search of scientific databases such as IranDoc, SID, Magiran, and the Scientific Information Center of the Academic Center for Education, Culture and Research (ACECR), among others, within the field of geographical studies yielded 51 articles using the keyword “climatic zoning.” Of these, only 18 articles specifically addressed climatic zoning, and this subset constituted the statistical sample of climatology-related articles analyzed in the present study.
To examine differences in the distribution of methods used to study climatic elements in climate-responsive architectural research, the chi-square test was applied. Data analysis was performed using SPSS software (version 25).
Findings
Among the reviewed articles, the highest number of publications appeared in the journals Housing and Rural Environment and Honar-ha-ye Ziba, whereas the lowest number were published in Iranian Architecture and Urban Planning and Iranian Restoration and Architecture.
The methods used for applying climatic data in climate-responsive architectural studies can be classified into descriptive, quantitative, and field-based approaches. The descriptive approach is further divided into quantitative, qualitative, and mixed (quantitative–qualitative) categories. Descriptive quantitative studies employ statistical descriptive methods to present the climatic characteristics of the study areas, including mean temperature, precipitation, wind speed and direction, and similar parameters. In descriptive–qualitative studies, authors describe the general climatic characteristics of the study areas by drawing upon the results of previous research, without presenting numerical data in the form of diagrams or charts. This approach represents the most prevalent use of climatic parameters in architectural studies (Gorji Mahlabani & Daneshvar, 2010; Bideli et al., 2020; Ansarimanesh et al., 2019; Barzegar et al., 2015; Bina, 2008; Darban & Salehi, 2020; Hashemi & Heidari, 2012; Ranjbar et al., 2010; Mahdavieh et al., 2020; Torabi, 2014; Bigdeli et al., 2019; Ghiasi & Kasmaie, 2019; Pour Ahmadi et al., 2019; Hosseini et al., 2012; Mofidi et al., 2013; Melatparast, 2010; Soltanzadeh & Ghaseminia, 2012; Sharif et al., 2017; Mofidi Shemirani & Moztarzadeh, 2016; Mahdavinezhad et al., 2016; Mahdavinezhad et al., 2017; Khodabakhshian & Shemirani, 2014; Moshiri, 2010; Karimi, 2012; Mofidi & Mamaghani Gazi Jahan, 2013; Zamani et al., 2017; Ghiabaklou, 2001; Amirkhani et al., 2009; Ghanbaran & Hosseinpour, 2016; Hashemi & Heidari, 2011; Gorji Mahlabani & Sanaee, 2010; Rahmatian et al., 2014; Zandimoheb, 2019; Gorji Mahlabani et al., 2012; Gholami & Kavian, 2017; Khosronia, 2017; Yousefipasha & Barzegar, 2018; Iranmanesh et al., 2015; Aminpour et al., 2017; Sheikh Bahaie, 2019; Sheikholeslami, 2012; Davtalab et al., 2016; Okhovat et al., 2011; Singeri & Abdolnaser, 2012; Khakpour, 2013; Razavipour & Zakeri, 2014; Zarei & Mirdehqan, 2016; Shahabinezhad et al., 2016; Zeinalian & Okhovat, 2017; Zareie et al., 2018; Raigani & Eslami, 2018; Abdolhoseyni, 2011; Nikghadam, 2013; Molanaie & Soleimani, 2016; Shariatmadari et al., 2019; Zohari & Azemati, 2020).
The mixed descriptive approach combines both quantitative and qualitative methods (Molae et al., 2020; Bideli et al., 2020; Baghaie et al., 2015; Barzegar et al., 2015; Nooshin et al., 2022; Bina, 2008; Salighe & Saadat, 2020; Hashemi & Heidari, 2011; Ranjbar et al., 2010; Mehdizadeh Seraj, 2019). In the quantitative approach, statistical tests are applied to analyze trends in climatic parameters and to perform climatic zoning of the study areas. Approximately 16.83% of the reviewed studies used this method to describe the climatic characteristics of the target regions (Rezaie et al., 2019; Sadeghi Ravesh & Tabatabaei, 2009; Pourdehghani & Gosili, 2015; Leilian et al., 2010; Amirkhani et al., 2009; Heidari, 2012; Tahbaz, 2011; Mahmudi & Nabavi, 2011; Taban et al., 2012; Rostampour et al., 2020; Salighe & Saadat Joou, 2020; Silvayeh & Asefi, 2019; Tahbaz & Jalilian, 2016; Gorji et al., 2012; Mehdizadeh & Ahadi, 2013; Aminpour et al., 2017; Shaeri et al., 2018; Ghiabaklou, 2003). Notably, Köppen climatic classification and temperature-based zoning methods, such as the use of ombrothermic curves were the most frequently applied techniques within this category, accounting for 58% of the studies (Nikghadam et al., 2016; Mofidi et al., 2013; Amirifard et al., 2021; Yaran & Mehranfar, 2014).
Field-based collection of climatic elements was employed in only 3.96% of the reviewed studies, representing the least frequently used methodological approach in climate-responsive architectural research (Dahar et al., 2020; Pesaran et al., 2019; Fooladi et al., 2016; Taghvaie et al., 2022; Abdolhoseyni, 2011; Norouzian Maleki et al., 2010).
A statistically significant difference was observed among the studied groups with respect to the methods employed, and descriptive qualitative and mixed approaches were the most widely used in the reviewed journals. Therefore, climate-responsive architectural studies have largely relied on qualitative descriptions of regional climatic characteristics, in conjunction with the findings and interpretations of previous research.
Among the climatic elements examined, temperature was the most frequently used parameter, accounting for 35.34% of the studies. In addition, combinations of climatic elements including wind, precipitation, temperature, and humidity were applied in 19.81% of climatic zoning analyses.
With respect to climatic diversity, the most frequently investigated climate types included hot and dry, hot and humid, cold, temperate and humid climates, as well as studies addressing broader climatic diversity. Approximately 7% of the reviewed articles consisted of historical background studies, single-building case studies, or review papers in which no specific climate type was explicitly identified.
Regarding climatic zoning techniques, temperature–precipitation-based methods and the Köppen–Geiger classification showed the highest frequency of application. Other methods such as cluster-based factor analysis, multivariate statistical analysis, integration of effective layers in GIS, Kriging interpolation, and the Littin ski method were used less frequently.
In terms of spatial coverage, 55.55% of the case studies conducted in Iran focused on individual provinces, including Razavi and South Khorasan, Lorestan, Markazi, Khuzestan, Urmia, East and West Azerbaijan, Yazd, Chaharmahal and Bakhtiari, and Sistan and Baluchestan. Furthermore, 27.77% of climatic zoning studies were conducted in specific regions of Iran, while 16.66% addressed the country as a whole
Discussion
The aim of this article was to examine the adequacy of the use of climatic data and the diversity of commonly applied methods in climate-related architectural studies. Another objective of the study was to review research on climatic zoning and the diversity of case studies in order to address the needs of architectural research concerned with climate-responsive design.
Based on the findings, during the studied period, the journals Housing and Rural Environment and Honar-ha-ye Ziba published the highest number of articles related to climate-responsive architecture. Among the reviewed studies in this field, 45.54% did not employ any climatic data in the form of numerical descriptive representation or quantitative analysis of climatic characteristics, while 11.88% relied on a combination of quantitative presentation of climatic data and the reporting of climatic zoning results from previous studies. Consequently, a substantial proportion of climate-related architectural research has depended on the findings of earlier climatic zoning studies and on descriptive accounts of climatic elements, highlighting the need for greater attention to both the quality and quantity of climatic zoning research.
Furthermore, searches conducted using the keyword “climatic zoning” indicate that only 18 articles, despite explicitly using this keyword, presented updated results on the classification of regional climates through diverse and contemporary methods. This suggests that the number of research articles produced between 2001 and 2020 is insufficient to adequately meet the needs of researchers in the field of climate-responsive architecture. Moreover, none of the climatic zoning studies conducted within the field of geography were utilized in climate-related architectural research.
Climatic zoning based on combinations of climatic elements exhibited the highest frequency in climate-responsive architectural studies (Tahbaz & Jalilian, 2016; Tahbaz, 2007; Vafamehr & Sanaian, 2009; Asefi et al., 2016; Nasrollahi & Abarghie, 2016), followed by the Köppen–Geiger method (Nikghadam et al., 2016; Mofidi et al., 2014; Amirifard et al., 2021; Yaran & Mehranfar, 2014), which has also been recognized as an effective approach to climatic zoning. Among individual climatic elements, temperature, followed by the combined use of precipitation, temperature, wind, and humidity, was most frequently employed in describing climatic characteristics and zoning the studied regions in climate-responsive architectural research. The prevalence of architectural climate studies conducted between 2001 and 2020 in hot and dry regions (45%) is particularly notable. However, according to the Ganji classification (Kasmaee, 2003), 47% of climatic zoning studies were carried out in the northwestern and northern regions of Iran, characterized by cold, temperate, and humid climates.
At the same time, a substantial portion of climate-responsive architectural research, such as studies on the performance of double-skin façades, has been conducted in densely populated provinces such as Tehran and Alborz, and particularly within hot and dry climatic regions, due to political, cultural, and urban density characteristics. Accordingly, there is a clear need for climatic zoning studies in extensive provinces with dense urban development, including Tehran, Alborz, Isfahan, Gilan, Bushehr, and Ahvaz. Nevertheless, none of the reviewed climatic zoning studies included these regions as case study areas.
The findings further indicate that climate-responsive architectural research in Iran has disproportionately focused on hot and dry regions compared to other climatic zones. In describing the climatic characteristics of study areas, these studies have largely relied on qualitative and quantitative descriptive accounts, as well as the findings of previous research. Despite this emphasis, adequate climatic zoning studies specifically addressing hot and dry regions were lacking during the 2001–2020 period. In geographical research, climatic zoning has tended to emphasize the integration of influential climatic layers, particularly precipitation and temperature. In contrast, climate-responsive architectural studies have largely relied on earlier classification systems and on descriptive presentations of climatic elements to characterize regional climates (Gorji Mahlabani & Daneshvar, 2010; Bideli et al., 2020; Ansarimanesh et al., 2019; Barzegar et al., 2015; Bina, 2008; Salighe & Saadatjou, 2020; Darban & Salehi, 2020; Hashemi & Heidari, 2012; Ranjbar et al., 2010; Mahdavieh et al., 2020; Torabi, 2014; Bigdeli et al., 2019; Ghiasi & Kasmaie, 2019; Pour Ahmadi et al., 2019; Hosseini et al., 2012; Mofidi et al., 2016; Melatparast, 2010; Soltanzadeh & Ghaseminia, 2012; Sharif et al., 2017; Silvayeh & Asefi, 2019; Mofidi Shemirani & Moztarzadeh, 2016; Mahdavinezhad et al., 2016; Mahdavinezhad & Mansour Pour, 2016; Khodabakhshian & Shemirani, 2014; Moshiri, 2010; Karimi, 2012; Mofidi & Mamaghani Gazi Jahan, 2013; Zamani et al., 2017; Ghiabaklou, 2001; Amirkhani et al., 2009; Ghanbaran & Hosseinpour, 2016; Hashemi & Heidari, 2011; Gorji Mahlabani & Sanaee, 2010; Rahmatian et al., 2014; Rostampour et al., 2020; Zandimoheb, 2019; Gorji Mahlabani et al., 2012; Movahed & Fatahi, 2013; Gholami & Kavian, 2017; Khosronia, 2017; Yousefipasha & Barzegar, 2018; Iranmanesh et al., 2015; Amin Pour et al., 2017; Sheikh Bahaie, 2019; Sheikholeslami, 2012; Farshchi, 2010; Davtalab et al., 2016; Zomorodian & Pourdeihimi, 2017).
Based on these findings, conducting climatic zoning studies in hot and dry regions, particularly in provinces with high building density such as Tehran is strongly recommended to address research needs related to topics such as the performance of double-skin buildings. Furthermore, it is suggested that future climatic zoning studies prioritize the use of established and sufficiently accurate methods, such as the Köppen–Geiger classification, rather than relying solely on the combination of climatic parameters
Conclusion
Although climatic zoning studies have been conducted for certain regions of Iran over the past decade and have produced extensive results, none of these findings have been utilized in climate-responsive architectural studies. Moreover, a lack of diversity in climatic studies within hot and dry regions, particularly for major cities such as Tehran was observed. This is noteworthy given that many climate-related architectural studies have been carried out in large Iranian cities, including Tehran, Isfahan, Mashhad, Shiraz, and Tabriz. These cities not only possess a rich architectural heritage but also, due to their demographic, social, political, and cultural potential, are highly likely to host prominent and landmark buildings in the coming years. Accordingly, there is a clear need to conduct climatic zoning studies for these regions using reliable and well-established methods, such as the Köppen–Geiger classification.
Acknowledgments: The authors report no acknowledgments.
Ethical Permission: The authors report no ethical approval requirements.
Conflict of Interest: The authors declare no conflict of interest.
Author Contributions: Siadati FS (First Author), Main Researcher/Discussion Writer (50%);
Fayaz R (Second Author), Assistant Researcher/Discussion Writer (30%); Nikghadam N (Third Author), Statistical Analyst (20%)
Funding: This article is derived from the doctoral dissertation of Faryal Sadat Siadati entitled “Proposing an Optimal Double-Skin Façade Model for Office Buildings in the Hot and Dry Climate of Iran,” conducted under the supervision of Dr. Rima Fayyaz and with consultation from Dr. Niloufar Nikghadam at Islamic Azad University, South Tehran Branch. All research expenses were covered by the doctoral candidate, and no external funding or financial support was received