An architect or contractor who, for a lump sum, takes charge of the construction of a building, or of any other work, in view of a plan agreed upon with the owner of the ground, cannot demand an increase in the price, even if that of the materials or wages has increased, but he may do so when any change increasing the work should be made in the plans, provided the owner has given his authorization.\nHistory —Civil Code, 1930, § 1485.
Puerto Rico Legal Code