Abstract
In the appraisal of the market value of the properties are applied two important surface indexes: the market surface ratio of the secondary surfaces and the ratio of the site value to total value (allocation method). The measure of both these indexes can be revealed difficult: the data collection of the surface trade ratio in the market can get different results and in practice often the valuer refolds on the fixed coefficients brought in the handbooks and in the circulars of the public administration; the appraisal of the ratio of the site, especially in the central zones and for ancient buildings, where besides the incidence is higher, is developed extrapolating the ratios from the peripheral zones for new building or falling back on the publications of real estate sector.
For the market comparison methods are proposed a series of test of surface trade ratio and land value ratio to foresee the effect on the appraisal result.