Method of Modulation and Sizing of Historic Architecture

Both the base duodecimal arithmetic and geometrical procedures derived from the diagonal of a square were recurrent resources in the design and construction of past architecture. The hypothesis of a double metric scale justifies the modulation size in buildings throughout a long historical period, using a simple and practical procedure whose fundamentals and characteristics are presented here. Validation by other researchers of the method proposed, would be a milestone in the history of the proportion of architecture, a step towards gaining knowledge of a common metric system used since ancient times in the construction of important buildings.