In a residential portfolio valuation, a qualified assessment at the individual property level is not feasible, especially in the early stages of a transaction, due to time and cost reasons. Stefan Haas is developing a valuation methodology that standardizes the determination of a portfolio expected value and also enables quantitative risk measurement. Despite the complexity of real estate-specific issues, it has been possible to develop a valuation model that is both theoretically sound and provides comprehensible results for practical application.