Public Supply of Rental Housing under The National Housing Program – Possible Scenarios of Changes in the Rental Market. The aim of the study is to conduct analyzes of possible scenarios of changes in the housing sector after launching the Plus Apartment Program. Therefore, the purpose of housing policy should be to increase the availability of apartments in the form of rental. The research problem is the answer to the following questions: Is it feasible to intervene in the construction market to increase rental supply? What impact on the private rental market may have on the supply of public housing about the rent lower than the market? What impact can the supply of housing under the Plus Apartment Program on the investment and rental of housing for social building society? In which municipalities and on what scale should I implement the Plus Apartment Program? The study hypothesized that the impact of the public supply of apartments for rent under the Plus Apartment Program on residential markets will depend on local conditions of market development and local housing situation.