Energy efficiency is defined as matter of obtaining balance between the energy gained and the sacrifices necessary to bring about this gain . A building in Sweden, now in the designing stage, will be testing a new design process to reach the highest possible level of energy efficiency. (Construction to take place in 1997, and commissioning in 1998.).All major services and systems for this building will be optimized, via marginal profitability analysis, in order to give maximum contribution to the integrated energy efficiency (both electricity and heat). Energy conservation will be achieved by technical solutions and measures regarding: 1) Maximum use of daylighting with energy efficient lighting systems; 2) All-air system with desiccant or indirect evaporative cooling; 3) Energy efficient equipment in offices and other areas; 4) Maximum use of the thermal mass of the building structure.