A substantial amount of publicly available and private information pertaining to buildings is inputted into a computerized data base programmed to produce statistical standards (norms) which can then serve as a basis for subsequent comparison with particular, selected, structures. The information is organized and formatted to facilitate the analysis of various income and expense items (including the taxes) pertaining to selected structures. Various special screens (forms) are used to aid in entering data pertaining to selected buildings and portfolios of buildings into the computerized data base and to interactively assist in the analysis of the data entered in view of the information contained in the computerized data base including the generation and display of significant statistical information regarding the selected properties and the generation of various reports. The system includes programs for simultaneously displaying the actual and adjusted values of selected income and expense items for the generation of reports for local property and/or income tax purposes, assessments determination, management purposes and/or investment decisions.