Abstract
In the traditional architecture of Shushtar, as one of the architectural types of Iran, there are examples of architectural regionalism approach. Houses decorated with motifs, designs and decorations, which have given a special glory to the architecture of this city with a combination of three materials, stone, plaster and brick. A small part of the patterns and decorations of these houses is in the entrance area of the main door, but most of the decorations and arrays are in the interior of the houses of this city. Most of these houses are known by the name of the owner or owner. One of these houses is “GhasabNejad” house. This house is a dominant example of Shushtar decorated houses. This research is done with the aim of getting to know better about the decorative elements and motifs of Shushtar city as an example of warm and dry regional architecture and at the end of the article, the question of what and why are the three decorative motifs and elements of Shushtar Butcher House, based on the critical regionalism approach The answer is given. The information of this article was collected in the field using visual and library evidence and presented in a descriptive and analytical way.
Keywords: Shushtar Traditional Architecture, Ghasabnejad House, Critical Regionalism, Anthology Networks, Brick and Stone Decorations.

Introduction
Shushtar is one of the old cities of Iran, where there are monuments from different historical periods. This city was prominent as the center of Khuzestan during the Qajar period and most of the existing works of residential architecture with decorative elements are attributed to this period. Among the important buildings of this city, we can mention the “Afzal” complex, the houses of “Marashi”, “Mustafi”, “Bakal-Sadat”, “Gazer”, “Qasabnejad” and the like. In addition to the specific and functional architecture, the mentioned buildings are decorated with arrays that stand out like a beautiful painting on the walls. Harmonious proportions, various visual elements including line, surface, volume and texture in combination with light and shadow, appropriate combination of components such as lungs, frames and borders, headers and the quiet whisper of change from pattern to frame and from frame to surface of some of these buildings. The city built something that the concept of well-formed calligraphy tradition can be applied to parts of these buildings. In the area surrounded by the two branches of the Karun River in Shushtar, the building studied in this research is GhasabNejad’s house. This building located in “Dol Dol (Moghi)” neighborhood is located in the vicinity of Gazer’s house and belongs to the Qajar period, which was renovated in 2016 under national registration number 29157 and at the end of 2016. This house consists of four floors, ground floor, first floor, Shabestan, and Shawadan. Due to its area, this house is one of the historical, large and highly decorated houses of Shushtar and has triple motifs of stone, plaster and brick. According to what has been said, the purpose of the current research is to study the types of motifs used in GhasabNejad’s house in order to better identify the historical houses of Iran, and finally to the question of what and why are the motifs and three decorative elements of Shushtar’s Butcher’s house, based on the approach of critical regionalism The answer is given. The discussion about the architectural and structural elements of this house, such as arches, columns and the like, is out of the scope of this research.

Theoretical foundations
Since this research focuses on architectural decorations, the three decorative elements of butcher houses are analyzed as an example of Shushtar houses, based on the approach of regional architects. Critical regionalism is a middle ground between the two, with regional preferences that are not identical to native architecture. From Frampton’s point of view, local cultures should be viewed in a way that is modern and has the ability to become modern. Achieving critical regionalism is the exploitation of local characteristics inside and outside the modern building form and does not mean returning to traditional building. Frampton calls this type of architecture, which resists the trend of homogenization of world architecture, as critical regionalism (Tadjdee and Islami 2018: 22, quoted by Frampton). In Table 1, the features of regionalist architecture are stated in terms of Islamic and modernism.

GhasabNejad’s house 
GhasabNejad’s house is one of the historical houses of Shushtar city, which is located in “Doldol (Moghi)” neighborhood, adjacent to “Gazer” house. This house, like most of the remaining traditional houses in this city, belongs to the Qajar period, which, in addition to the traditional architecture, has different decorative arrays. About the history of ownership of this house (Fig.  1) (Fig.  2) shows the plan of these two complexes. Currently, both parts of this historical house have been registered in the national register. The architect of this house is “Mohammed Taghi Mimarbashi Shushtri” according to the inscription that is located near the porch of its outer part (Gazar House) and the date of completion of the building is 1277 AH (photos 3).

Decorations of GhasabNejad house
GhasabNejad house has triple decorations of stone, plaster and brick. Brick patterns are like (Fig. 4). Another part of the decorations of the old houses of Shushtar is the butcher house of Setonah, which is built with materials such as stone and brick, and their decorations include the motifs of “Kartele”, “Baik” and “Congress” (Fig. 5). Plaster grids are among other motifs used in Shushtar houses, which are placed on the facade of the building and usually between the arches and above the windows. In addition to decorative use, these elements were used to ventilate the air and let light in. (Fig.  6). Fig. 7, shows the three decorations of GhasabNejad’s house. The stone decorations include animal and plant motifs, each of which has different meanings. (10) The location of the plaster grids is also shown. Also, pictures (11 and 12) show other brick motifs in the butcher’s house building.

Conclusion
Three elements, brick, stone and plaster, are the main materials of Shushtar architecture and its decorative arrays, which were used in GhasabNejad’s house with refinement and merit in the structure and decorations of the building. The materials, motifs, form and decorations are common in most Shushtar houses, with the difference that each architect has made changes in them according to the personal taste and interest or the opinion of the owner of that building. The stone carvings of the butcher’s house include animal motifs such as peacocks, parrots and plant motifs such as lotus flowers. The roles of these animals and plants are sometimes mythical and probably liked by the architect or owner of the building and according to the cultural conditions of that time and the owner’s financial ability. The motifs of Golchin Gachi networks are a combination of Islamic geometric Chinese knot motifs and its famous shamsehs, and one case is a combination of Chinese knot and cedar tree. The decorative brick motifs of this house are arranged on the top of the porch and the edges around it. There are three motifs, Serzi Sarbala (in the local language), on the top of the porches, and complex key armband motifs, and one, two, and three plains, are engraved on their margins. The technique of performing brick patterns above the porch is flat and their edges are highlighted. The pattern of the columns was from the Moqrans design shared by the houses of Shushtar, such as the pattern of Kartele, Congress and Beyk. Some roles have been named according to their resemblance to something else. Like the pattern of the head below the head, which is similar to the pattern of the mat.
The reason for the use of these decorations is to align with Shushtar’s traditional architecture and this feature is consistent with the regional preferences side of the critical regionalists’ approach in architecture. Following this tradition, there are brick patterns on the front of the porches and on the outside of the houses, stone patterns are on some of the gates, considering the structural function of the stone, and plaster grids are also implemented in the upper part of the building. Among the three elements used in GhasabNejad’s house, the patterns of the front bricks of the porches were functional, mostly decorative, and the stone carvings and plastered grids had both decorative and practical functions. In this building, in addition to the decorative function, these three elements have been used to express the spiritual, material or traditional interests of the owner of the property. Among the three mentioned elements, according to the long-standing media tradition, stones have always been the representation of the personal feelings of the architect or the owner of the building.
Relying on the approach of critical regionalism, it can be said that the stone element is a special functional and decorative element in the architectural structure of Shushtar city as well as GhasabNejad’s house, which makes the architecture of this city different even compared to its neighbor, Dezful. It originates from the stone bed of the city and the presence of stone mines near the city of Shushtar. It seems that the architects of Shushtar have taken advantage of their unique native and regional element in building in the right place. Also, perhaps the use of stone for personal expression reminds us that the oldest means of expressing human emotions in a space other than its original place, i.e. mountains and deserts in the man-made environment, is still capable of expressing human emotions. The tradition that started from the heart of the mountains, rocks and caves continued in the cemeteries and the like, and in public and private places, it has a dual function of structure and media.
  The adaptation of architectural elements, especially the triple arrays of GhasabNejad house as a relatively complete example of Shushtar’s traditional houses, showed that the architecture of this house is compatible with most of the features of the critical regionalism approach, despite the time difference and the youth of the critical regionalist architecture discussion with ups and downs. The use of stone in the building as a special local element and the presence of a parrot in the stone bearer inscriptions as a non-regional bird in this building are two important features of the critical regionalism approach that has been digested in Shushtar’s architecture.