[en] Considering that housing is the place in which the human being spends most of his life time, the treatment and study of environmental conditioning in this one is of the utmost importance, for the case of the investigation, will be on the appropriate natural light conditioning considering the solar geometry, is this case of the tropic. The duty aims to study natural lighting in the houses of PREVI in Lima Peru, proposals by the Spanish architects José Luis Íñiguez de Ozoño to then apply them to the Madrid context, since, these were projected apparently considering a solar path similar to that of the Iberian peninsula but not to that of the original site where they are located (tropic of Capricorn), this may be due to legislation which did not provide for or require compliance with light aspects in the building, and even today, the national regulations on Peruvian buildings are questionable and at present there are still faults in the field of natural lighting.