Typology of Tarmeh as a Semi-open Space in Vernacular Architecture of Bushehr

Over the years, vernacular architecture of each region has been developed in harmony with climate and context in order to provide residence comfort. In southern part of Iran, Bushehr architecture has unique features and distinctive architectural creativity to adapt to the hot and humid climate of the region. This paper aims to define the typology of semi open space Tarmeh. The characteristics of this space in the old town Bushehr have been described in a descriptive-analytical way. For this purpose, 16 buildings with Tarmeh have been selected and analyzed. The research have been accomplished in four stages including historical background and documentation study, case studies identification and survey, data classification and analysis, and definition of various types of Tarmeh. In order to do so, different types of Tarmeh have been studied in terms of location, orientation, architectural features, function, geometry and proportions, access and privacy. The results of the study divided Tarmeh into two categories of external and internal ones which can be distinguished in various forms. Based on the results the function and geometry of Tarmeh is in compliance with the most important passive strategies to provide thermal comfort in such climate including sun protection, shading, and ventilation and air movements. Various functions of Tarameh include seasonal living space, corridor access and climatic function. In the case studies prevalent orientation of Tarmeh is set according to the sea. So in addition to provide proper view, it catches the breezes and though leads the wind flow into the building spaces in depth. The results of the study show that Tarmeh has been used with the aim of benefiting from various aspects as a climatic element, architecture and accessibility factor and geometry, shape and location of two types of internal and external Tarmeh are defined based on the sea orientation to receive the prevailing wind.
Keywords: Typology, Bushehr, Semi-open Space, Hot-humid, Tarmeh.
Introduction
Vernacular architecture always reflects the interrelationship between culture and environment and their interactions with each other. In Iranian architecture, the formation of a building is based on the combination of three patterns of open space, closed and semi-open (Haeri, 2009). Semi-open spaces have been an important part of Iran’s architecture, which in addition to strengthening the architectural relationship with nature, had various climatic, cultural, physical, and psychological functions. The history of semi-open spaces in Iran dates back to more than two thousand years ago as the Achaemenid period. The presence of a porch in the palaces of Pasargada and the Apadana Palace in Persepolis during the Achaemenid period, the Hetra Palace in the Parthian period and the Sarvestan Palace and the Castle of the Girl in the Sassanid period confirm this point. In vernacular architecture of Bushehr, there are different types of semi-open spaces, among which we can name Shanashir, Tarmeh, Bon and Pish-Bon. Due to the climatic conditions of Bushehr and high temperature and humidity, the use of air flow and ventilation is one of the most important strategies for climate design.
 So identifying the types of semi-open spaces and their typology can be the first step in the direction and modeling and their application in contemporary architecture. Limited research has been done on semi-open spaces in the hot and humid climate of Bushehr and no research has been done on the semi-open space of Tarmeh. The present article defines the typologies and different functions of the semi-open space of Tarmeh in the vernacular architecture of Bushehr. In order to do so, different types of Tarmeh have been studied in terms of location, orientation, architectural features, function, geometry and proportions, access and privacy. The research hypothesis is that Tarmeh has been used with th aim of benefiting from various aspects as a climatic element, architecture and accessibility factor and geometry, shape and location of two types of internal and external Tarmeh are defined basesd on the sea orientation to receive the prevailing wind. This article aims to define the characteristics of Tarmeh in the vernacular architecture of Bushehr using descriptive-analytical research method to classify its typology. The research method is qualitative research with case study strategy. The research stages include four stages of studying documents and historical background, identifying and examining case studies and samples, analyzing documents and classifying data and compiling different types of Tarmeh.
 
Identified Traces
In Bushehr architecture, there are various combinations of connections between closed, open and semi-open spaces. In the case of Tarmeh, geometry and its proportions depend on the geometry and overall dimensions of the building. The minimum width of the floor is equal to the width of a two-way staircase and its length is equal to the length of one or more rooms. The width of Tarmeh in the studied samples is between 1 to 4.5 meters and in most cases it is equal to 2.5 meters. The length of Tarmeh in the samples is a maximum of 25.8 and a minimum of 3 meters and an average of 10 meters, although the determining factor is the length of Tarmeh, its location and the length of its location. The most common form of Tarmeh is a linear form with a rectangle with proportions. However, by combining the linear geometry of Tarmehs, different types of geometric shapes have been created in different ways. External scales in linear forms, L, T, H and U with an average width of 2.4-3 m and variable length, there are different proportions. The inner ridges are in one, two, three or four sides of the yard and are between 1.1 and 2 meters wide. The height of Tarmeh is usually equal to the height of the floor and is on average 4-4.5 meters. In all the studied samples, the orientations of the external Tarmeh and its location have been considered depend on the sea to receive the prevailing wind. In all coastal cases, Tarmeh is oriented towards the sea and to the northwest and west except in case number 15. In the cases located within the context and not on the seashore, Tarmeh has been constructed in the northwest and west directions and in only three samples it is in the east direction. In four buildings, in addition to the Tarmeh, there is also Shanashir. The use of external Taremeh in combination with indoor Shanashir around the courtyard to create access is common. Indoor and outdoor Tarmeh are mainly located in the vicinity of closed spaces, including 3 doors and 5 doors. In 14 case studies, Tarmeh is on the second floor, in two cases on the first floor and in one case on the third floor.
 
Conclusion
Tarmeh space has been used to benefit various aspects as a climatic architectural element and the space providing privacy. So a common example of Tarmeh can be evaluated from three perspectives: climate performance, architectural performance, and privacy. The climatic effects of Tarmeh can be examined in two ways of reduction in received radiation and increasing ventilation. In addition to creating a more favorable space in terms of thermal comfort and visibility, it also plays a major role in moderating the thermal conditions of its adjacent enclosed space. Lower humidity and more air flow in Tarmeh compared to the adjacent closed spaces, have make it the favorable space for rest, gathering, doing housework and daily activities, temporary seasonal living, corridor and communication space. On the above floors, Tarmeh is the most common space to create access to the other spaces and visual privacy. The results of the study show that Tarmeh has been used with the aim of benefiting from various aspects as a climatic element, architecture and accessibility factor and geometry, shape and location of two types of internal and external Tarmeh are defined based on the sea orientation to receive the prevailing wind.