A panj-dari is a traditional element of vernacular Persian architecture.
The word comes from "panj" (five) and "dar" (window or door), meaning "five windowed room".
By definition, a panjdari is a large room that is often flanked to the main talar of the house, and most often connected to a large balcony, where 5 large contiguous windows provide primary views to the main courtyard of the house.
In modern terms, the room would be the equivalent of the "living room" of the house. However, traditional Persian houses were very large and had many rooms. The panj-dari room was therefore a main daily hub of the inhabitants.