The paper examines basic concepts related to real estate recording, the real estate register and real estate mass valuation. It describes real estate mass valuation models and the key data included in the real estate register. The paper also describes the procedure for calculating the generalized real estate market value for various types of residential houses, a garage and farmhouse. By drawing on practical examples of buildings recorded in the building cadastre in the municipalities of Nova Gorica, Ajdovščina and Vipava, the paper shows how different approaches to record a real estate in the building cadastre affect the real estate's generalized market value. The last part of the paper provides a simulation of two possible ways to calculate the generalized market value of a residential house and a garage in a selected area. In the first example, the two buildings are recorded in the building cadastre as one building, while in the second example the house and the garage are recorded separately in the building cadastre as two different buildings.