The Vernacular Architecture of Gilan

Gilan is one of the northernmost provinces of Iran. Tucked against the Caspian Sea, Gilan is so humid and has such high yearly rainfall that Rasht, the capital, is known internationally as the “City of Silver Rains.” In the south, the Alborz Mountains trap the humidity and steam produced by the sea. Gilan province consists of two parts: the mountainous, forested southern areas and the plain of the Northern coastline. These geographic conditions have defined the architecture of the province. Many traditional and climate-responsive solutions have been devised to efficiently prevent moisture and humidity, provide natural ventilation, and navigate rainfall.

By studying the vernacular of this region, we can learn how architectures like this have engaged with their environments and how the people of these places have designed unique strategies for thermal comfort. In order to make the best use of natural ventilation and avoid having stagnant moisture, each element of a building is located apart from the others. In addition to being an effective sustainable architecture, this approach to design has resulted in an aesthetically-satisfying built environment with comfort and convenience for the people of Gilan. Generally, open peripheral spaces and sloped roofs are the most notable features of this architecture. Semi-open spaces and vivid layers of facades blend the outdoor and indoor, developing a close relationship between the residents and their surrounding environment.

As Gilan remains temperate but moist for most of the year, reducing humidity in residential buildings is key to providing comfort. Thus, enabling free air and wind circulation around the human body and environment is crucial. Design and construction in this region require meticulous solutions that can resist moisture penetration through the floor and ceiling. The vernacular buildings often employ the same key features of construction. Detailed below, these spaces and techniques illustrate the strong focus on environmental engagement in the architecture of Gilan.
Foundation: To prevent humidity and moisture from entering the building, the entire structure is lifted off the ground. The first layer is a cement pad foundation, with individual footers for layers of timber beams rotated 90 degrees and stacked on each other to build height. The size of the timber increases from the bottom to top to account for the structural loads.

Room: In this climate, rooms have changeable functions. One single room can be a bedroom, living room, dining room, or even kitchen. The rooms are seasonal, meaning that one room can be a bedroom and dining room during the cold season, but when it becomes warm again, all these activities might move to another space, like into the iwan.

Iwan: An iwan is a semi-open hall which connects open to enclosed spaces, and prevents rain from getting on the building’s inner, porous facade. The main iwan is bigger than any other room in the house and it serves as the living room. It is primarily located on the east or south side of the building and is often raised to provide better views and ventilation. The depth of the iwan is such that it can avert the undesirable sunlight in summer without blocking it in winter.

Peripheral passage: These are exterior spaces with two rows of columns. They serve several environmental as well as circulatory purposes, protecting from rainfall and direct sunlight during the warm season, providing a shaded space and allowing natural ventilation in the summer, and allowing a connection between the larger iwan.

Balcony: An iwan on the second or third floor functions as a balcony. Usually the balconies are raised above the iwan and the space beneath is used for storage.

Attic: A room adjacent to the balcony, usually for guests. Because of its location, it receives the best ventilation and view and has individual access to iwan.

Sloped Roof: Due to near-constant rainfall, roofs in this region are sloped. The empty space between the ceiling and sloped roof is designed to assist air flow and ventilation, and it is a suitable place for storing food during the year. Wood and natural fiber are the main construction materials in this architecture. Dense forests and rice farms are major sources for building materials. Areas that have access to clay incorporate the material into the roof for durability.

Gazebo: Gazebos are semi-open triangular or trapezoidal porches at the back or side of a building, created by the extension of the roof towards the end of the iwan. Traditionally used as a service space, a gazebo is located on the sides that receive most of the autumn and winter winds, and protect the house from heavy diagonal rainfall. The space below the gazebo is suitable for keeping livestock. Usually, there are no windows, thus preventing thermal exchange in the winter.