Automated Procedures Based on Market Comparison Approach in Italy

The question about objective valuation is linked on the one hand to theidenti fi cation of a large number of reliable sale data, on the other hand to the abilityto control the critical evaluation protocol. Automating the valuation process,ensured by computerization of real estate data properly detected, provides a con-crete answer to the problem of objectivity, allowing a signi fi cant control of thesubjective component which characterizes the more traditional appraisals.Automatic methods traditionally proposed at international level are often set onmultiple regression models, designed to build prediction functions that are validthroughout the study area, calibrating the coef fi cients on the basis of the real estatedata contained on the supporting database. In accordance with the InternationalValuation Standards, this paper proposes a different approach to automatedappraising that, far from the idea of de fi ning appraisal equations generally valid onthe basis of regression models, proposes the implementation of an automatic pro-cedure based on the Market Comparison Approach, with the aim to de fi ne equationsrelated to the peculiarities of a marketplace in a very circumscribed area. Theproposed method has been implemented through the Model Builder tool of ArcGISand has been tested on a pilot GIS for residential real estate properties.