Due to several different developments in the housing market it has become more difficult for medium income households to find an attainable private dwelling with corresponding mortgage. This has a negative influence on the number of transactions and deteriorates the flow through in the private housing sector. Since a first analysis showed that the mortgage lending restriction is the main restraining element, the emphasis of this thesis is on minimizing system risks by involving suitable stakeholders and thereby providing competitive mortgage loans. The result is a new business model that provides a structural improvement of the financial accessibility of private housing, which above all enables the medium income households to purchase private dwellings with an attainable mortgage. Furthermore, this Housing Investment Plan provides a good platform for the implementation of a standardized but diverse process and product and thus the ability to develop competing housing prices and energy efficient dwellings.