In evaluating an investment objective, one must take into account benefic effects, like local or regional economic development, trafic fluidization, but also negative effects like demolition of houses, movement of population, cropfield ocupation, noise, polution, etc. In all cases, the impact of constructions on the ambient has an intrinsis economic value. Thus in chosing the optimum investment project one must precisely estimate the costs and benefits of the investment, not just economic profit, but also the complex economic-ecologic profit, with long lasting implications