58|A FONDO The effective use of natural light as a way of improving energy efficiency If we stop to examine how lighting of interior spaces has evolved, we would see that the technology for the different components of the lighting installation has advanced drama- tically. New sources of light are increasingly efficient. But many times, when approaching the solution to a project and doing the calculations, be it in new projects or in the interven- tion of existing projects, we “forget” natural light.