Simultaneously with the formation of the industrial revolution in the world, with the sudden influx of the population from the villages to the cities, population settlement became an important issue in Iran during the first Pahlavi period. In the city of Qazvin, the first institutional houses were built in the 40s to 60s. The aim of this research is to obtain the model of physical-spatial structure of the first institutional houses of Qazvin city. In order to answer the main question, whether the institutional houses of Qazvin followed a specific physical-spatial pattern in their structure, four instances of the first institutional houses and their comparative comparison have been investigated and analyzed. In the first part, the descriptive-historical interpretative method was used qualitatively, and in the second part, by a survey method, sketches were prepared and drawn by AutoCAD 2019 software and using the software Depthmap 1014 and logical reasoning method have been used.The findings of the research showed that the geometric form, materials, micro spaces, the direction of the building, the separation of internal areas, the natural light, the preservation of visual privacy from the entrance and the depth of access to the internal spaces, are evident in almost the same way in all samples And the only difference between them is the extent of their dispersion on the site and the amount of use of green space. Finally, the physical-spatial structure of the samples are similar to each other to a great extent and follow a relatively uniform pattern.