We took a "city hotel" as investment in a project, and used NPV of two relating interests, which are Owner and Manager, as indexes of evaluation. We then maximized the indexes by bi-objective optimization applying GA in order to get "the Ratio of Room to Common space" which satisfies each interest's profitability to a high degree. As a result, "the Ratio of Room to Common space" took various values in relation of game of two relating interests, and there is a trade-off relationship shown as distribution of population considered to be the "Pareto Optimal Set".