The change of the rules governing the design and construction of buildings can involve the creation of housing with better sound insulation but at a higher cost, so it is recommended to evaluate the benefits of the actions undertaken to determine whether prevention or risk reduction results in improvements to welfare. This research compares the cost overrun that represents the acoustic isolation following the criteria of the CTE with the willingness to pay for the improvement. For this purpose are a parametric cost analysis and a contingent valuation respectively. The results suggest that the scenario used enables respondents to express their willingness to pay and that profits may exceed the costs of implementing more efficient sound insulation systems.