Due to the importance of the historical context of Dezful City, investigating historic buildings is necessary. But unfortunately, a large part of it is being destroyed. For this reason, it is essential to discover the guidelines and logic behind the architectural design of these buildings to help their reconstruction or restoration. Regrettably, there is no logical information about the components of this context and the reconstructions are usually done according to taste and based on architecture tested or personal preference. Therefore, it is necessary to find a logic behind these critical components that support the whole plan or parts of it in a particular style. The purpose of this research is to discover and find the logic behind the design of this building in the historical context of Dezful. Finding geometrical proportions can significantly help to reconstruct buildings better and more accurately. For this purpose, 30 historical houses of Dezful were randomly selected, and their input information was drawn in 2D form in AutoCAD. Then, the length, width, and height proportions were measured, and the obtained ratios were compared with the golden proportions and dynamic rectangles. This paper studies entrance based on ratios of $\sqrt 2$, $\sqrt 3$, $\sqrt 4$, $\sqrt 5$, $\sqrt {1.25}$ and φ (the golden section). The results show that golden proportions and proportions derived from dynamic rectangles are present in the wording of all cases. Moreover, the range of ratios in the plan is from 1.34 to 2, and the content of changes in the section is from 1.22 to 2. The results can help architects, and particularly building owners, to reconstruct based on existing logic by discovering the proportions of the entrances of the houses. It is possible to administer a part of the damaged tissue and estimate its dimensions and sizes because the proportions’ completeness can help revive half-destroyed historical buildings.