Abstract: In this study, the non-parametric method (DEA) has been used to estimate technical efficiencies of housing construction activities in different states of Iran based on the relevant data collected from provincial statistical centers during the years 2006-2009. The determination of factors affecting efficiency level is important as well as measurement efficiency. According to the results of the data envelopment analysis model, mean efficiencies of housing construction activities of the states were estimated to be 0.944 for Constant Returns to Scale (CRS) assumption. The research founded that only 37% of the states operate technically efficient and most of the technically efficient states had the opportunity to employ illegally migrated workers of neighboring countries in building construction activities using the advantages of lower level of payments and less commitment to the worker's insurance regulations in the country. The study concludes that, appropriate mechanisms should be implemented by the government for stabilizing housing environment within different states, ensuring maximal benefit of state housing expenditures, mobilizing private savings and finally providing subsidy assistance to the inefficient states on a multi-functional basis.