Introduction: Social indices of housing are the most suitable tools to measure the progress and achievement of the general goals of housing, and all levels, from individual to collective can be examined and evaluated via these indicators. In housing planning, the demographic-social conditions and settlements of the country should be taken into consideration, and also the provision of essential and additional services such as health, access to social services needed by the people should not be ignored. Indeed, this can contribute to spatial balance and social justice. Thus, the present study was aimed to investigate the factors affecting the need for housing with emphasis on social and demographic issues in Ilam.Data and Method: The present paper is applied in terms of purpose and descriptive-analytical (survey) in terms of method. The statistical population of the study consists of households in Ilam city where 383 households were selected as a statistical sample by cluster sampling. The data collection instrument was a researcher-made questionnaire whose validity was confirmed by face (content) and the reliability of Cronbach's alpha was verified as 0.841. Data analysis was performed using structural averages and the method of estimating residential per capita and net density.Results: The results show that the variables of age (0.21), gender (0.30), household dimension (0.18), household composition (0.38), life stages (0.18), tendency to innovation (0.24), residential origin (0.22) and migration (0.19) have a significant relationship with housing needs in Ilam. In a simultaneous investigation of the set of factors, the variables of household composition (33%), age (24%), and residential origin (21%) had the highest effect on the need for housing in Ilam, respectively. Also, according to the collected data and the use of quantitative residential model per capita and net density, it was found that the land required for the next ten years in Ilam is 14.7 hectares.Conclusion: Thus, estimating the age and sex changes of the population, new household formation trends, socio-economic aspects and the assigned share of household income to housing costs, and the conditions governing the processes of transforming a requirement into housing demand are effective. Hence, true understanding of the effect of these components, housing demand forecast and the effects of these important and determining factors should not be ignored.