The Mehr Housing Plan and the Housing Production Leap Act are among the most important and influential housing development policies in Iran. In this study, the Qazvin urban region has been selected as an exemplary case in the implementation of these policies in the country, with the aim of measuring the degree to which housing supply meets the needs of target groups by income deciles and its environmental assessment. The conceptual model of the study has outlined the general link between government intervention in the housing market and the spatial consequences of housing support policies, and in this context, changes such as population growth, density, and population patterns are analyzed. The current applied research has proceeded with a policy research approach and a mixed approach, using quantitative methods - such as statistical and spatial analysis - and qualitative methods - such as text analysis of semi-structured interviews. The findings show that both housing policies are correct from the actual volume of need for low-income groups for housing and access to government land in order to implement projects, creating unbalanced geography of housing in these plans. In the urban area of Mehregan and other housing sectors in other cities, it has fueled intra-provincial migration and exacerbated spatial disproportion in the distribution of the province's population. Also, due to the implementation of the Mehr Housing Plan, the population living at distances further from Qazvin city has increased significantly, presented in an unbalanced manner in the east and southeast of the urban complex and has caused the spatial development process of other areas to be interrupted or stagnant. The re-drafting of the Housing Production Leap Act within the Mehregan area will lead to a change in the trend of urban population growth and the accumulation of residential space for lower income deciles, and will lead to a change in the pattern of intercity travel and a redefinition of the functional boundaries of settlements. These changes reflect direct housing policy in redistribution and change in the spatial structure of the population in the Qazvin urban region.