The aim of this study is to produce a model that can simulate the positional real estate value, taking into account the transformation and expansion of urban areas. The model, called SiVa, is built on a geometric interpolation of points, raised from a matrix derived from Cellular Automata and using a fuzzy approach. The rules implemented by the Cellular Automata are a combination of logical and mathematical relationships that the model extracts on its own by deducing them from econometric analysis on values and features of the city of interest. For the city of Turin, a comparison has been completed – as verification and for a theoretical reflection – among the coefficient of the econometrical analysis with other two studies of this research: a survey of customer preferences (based on about 1300 interviews); and an analysis of historical series data (1990-2005).