54|CUADERNOS of utilizing only 5 per cent of useful roof surface to obtain savings of up to 40 with payback of 5 years implies maximizing the roof and a commitment to savings with the use of the best possible light: solar light. There are added benefits to thermal management of buildings: reduction of maintenance costs, extension of the useful life of conventional lighting and the effects associated with human behavior. The file of studies on the positive effect of the use of natural lighting on human behavior is enormous. ■ More information: www.lledosa.com “The energy efficiency market looks for savings conditioned by low investments. This is the only way efficiency makes sense. Substituting conventional lighting or introducing LEDS generates big savings but the investment is high”.