The aim of this work is to obtain explanatory equations for the stock-market value of construction and real estate companies, using the economic-financial information supplied by the same. Equations of fundamental valuation of construction and real estate companies will be calculated by means of combination of factor analysis of principal components and multiple regression, synthesizing the available information in the market and avoiding the frequent problem of multicollinearity. The contribution of this methodology to companies valuation increases on seeing the difficulties and the lack of precision when applying traditional methods. In this way, besides conventional methods, another additional criterion of valuation of companies is used, being useful in stock-market operations, in processes of concentration or for financial administration of these companies.