The new Town Planning Ordination Law passed on 5th November, 1999, establishes in articles 8 to 16, the different kinds, functions and responsibilities of members involved in the building process: property developer, designer, building contractor, manager of the carrying out of the Project and organizations and quality control laboratories, so different from the legislation applied until nowadays, the so called theory of responsibility for ruin, that appeared in the laws of the Supreme Court and was based on the article 1591 of the Civil Code, that only mentioned the architect and the building contractor to whom Jurisprudence included or added the figure of property developer. Besides this, in article 19, the law provides enough guarantees to be achieved during the building process so that it can be real the quality and delimit responsibilities among the different members taking part in the building process, that is, to impose an insurance to cover possible damages or defects in the materials or during the building process period of time.