The proper selection of building materials is important for sustainable development, and there is a clear need to design and construct buildings in a way that supports the concept of sustainable development. What is more, the environmental impact of construction material not only depends on the material itself and the other elements used in building, but also on the way they are put into place, the maintenance requirements, the system of longevity and the distance from the purchasing point to the construction site,etc. This means that the selection of materials or building systems requires the exactness of the LCA. Energy in buildings can be categorized in two types: the amount of energy required for the maintenance/servicing of a building during its useful life operating energy (OE) and the energy capital represented by the building materials used in the production of a building embodied energy (EE). A study of both these types of energy consumption is required for a complete understanding of building energy needs. A building’s embodied energy can vary greatly depending on the choice of building materials and techniques. Reinforced concrete walls, fired clay brick masonry,concrete block masonry and beam and block slabs form part of the common conventional construction systems used in the main structure of buildings in Spain. Similar building systems can be found in many other developed and developing countries.