This article identifies the significance of rooms and the role of their design in satisfaction of the recent habitants, in Iranian architecture. Accordingly, some guidelines and criteria are presented to optimize dimensions and number of different types of rooms in housing design and could be used in residential building codes. In a review of recent ordinary dwelling unit plans in Iran, we observe that the common big living spaces that usually attach to an open kitchen, are recognized as the basic part of contemporary housing design. So in such cases, the other spaces especially the private or family rooms, are formed after that without any relevance to the real needs of the habitants. In this condition, there are some uniform and single purpose rooms in dwelling units without any clear identity, and each one is called by an individual name such as bedroom or living room; But survey on the room patterns in Iranian past architecture, shows that they were designed and located with different concepts, based on the various cultural, geographical and climatic conditions. In the past architecture, rooms were often named upon their figure or shape (like the Pealy or Talar), number of their windows or external door ways (like the Panj-dari), location in house (Bala-khaneh), the term of service or using time (Zemestan-neshin), and were rarely named according to their special or individual function (like the Bastar-gah). Because, the current activities in such rooms were often various and they had multi purpose and flexible roles. Hence in the some regions of Iran, houses are still presented with the total number of their rooms (like the five room house), and not with the number of their bedrooms .The result of a field study carried out in several residential complexes in different regions in Iran also shows that the rooms with similar shapes and areas could have some different arrangements and functions formed by habitants for every unit in relation with their various population and social, economical and cultural conditions. In the cases that their design, dimensions and the number of rooms have no coherency with the conditions of habitants, the home can not provide their comfort and satisfaction, and can cause several disorders in their life. As regards the deficiency in possible dwelling areas for middle and low income housing in Iran, it is necessary to define manifold activities and functions for rooms rather than the ordinary plans. So in the configuration of spaces in housing design, besides observation of the technical aims such as stability, safety and health, we should have some other functional provisions , amongst: to supply required separate locations or spaces with adaptability to create and develop sufficient private or family sanctums . In this process, we should provide diversity in the rooms based on better recognition of the target people, and look ahead to flexibility and poly functionality on the room planning.
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