The 19th century, during the Qajar period, was the birthplace of colonial powers, especially Russia and England, in Iran. The conflict and confrontation of the main actors of this colonialism led to the separation of vast parts of eastern Iran. Sistan was no exception to this rule. The British, in line with their policy of creating buffer states and protecting India, despite the insistence of Naser al-Din Shah, divided Sistan into Main Sistan and Outer Sistan. After these divisions, and to weaken the Russians in Sistan and keep them away from India, they established offices such as the Consulate and the Bank of Iran and Britain. This article aims to understand the architectural features of these two buildings and the extent of their influence on the vernacular architecture of the region. The research method is descriptive-analytical, relying on documentary and library studies, content analysis of historical texts, and data collection through documented and historical methods. Additionally, part of the data collection is done using observation and interviews. Studies show that in constructing these two buildings, the British, in addition to paying attention to the general architectural type of buildings built by themselves in other colonial areas, also considered the region's vernacular architecture and the climatic conditions of Sistan.