Design and construction to achieve a minimum use of energy, design and construction of zero energy buildings differ significantly in their formal image of conventional buildings. In buildings of conventional design, the emphasis is usually on reducing initial construction costs to a minimum. The designers do not consider the costs of maintenance, operation, air conditioning, life cycle analysis of energy content to meet the limit set out in the building codes of the place. In the EEC’s position every important decision on the selection edilicio each subsystem is evaluated in terms of its impact on future energy demand, for which uses the technique of energy analysis of the life cycle. EEC designers support an increase initial construction cost if by this they can reduce energy demand and operating costs.A postulate for the design of a CES is first energy. In addition to using renewable energy, zero energy buildings are also designed to use the energy gained from other sources, including appliances, efficient lighting and use of metabolic heat (people). The buildings are optimized to take energy from the sun (passive house), use of thermal mass in order to maintain a constant internal temperature regardless of external temperature variations, further raising the average temperature inside in varying degrees in order to achieve the hygrothermal comfort with the help of thermal insulation or superinsulation. At present there all the knowledge and mature technology to build a EEC.Designers typically use sophisticated simulation tools that allow us to consider a wide range of design variables such as building orientation (relative to the sun), the type and location of windows, the shadows cast by buildings or by the building on itself, the depth of the glaze on the exterior surface of walls, insulation values at home subsystem edilicio, sensible heat content of air and latent heat, the efficiency of heating, lighting and other equipment as well as climate local. These simulations help designers to know how to behave before the building is constructed, and allow them to model the financial implications and construction costs. The architect or architectural designer usually hires an environmental consultant or bioclimatic for advice and initial design guidelines that will then be adjusted in the preliminary stage and project.Usually, the environmental consultant is composed of a multidisciplinary or interdisciplinary team involving architects, engineers, physicists, industrial designers and technologists. This depending on the size and complexity of the building.