ABSTRACT
In the context of building's sustainability, the treatment of the envelope is essential when proposing the requalification considering energy efficiency in buildings with architectural value to be preserved. Curt Siegel (1966) in his “Formas estructurales en la arquitectura moderna” (Structural Forms in Modern Architecture) presents an analytical study of modern architecture with reference to the concept of Structural Form. For Siegel, Structural Form is the unity between art and technique whose expression is also defined by the construction technique. This work presents a methodology for valuing the architectural heritage in order to propose guidelines when assessing the need for modifications to the facades (envelope) aiming energy efficiency retrofits, based on the concept of the expression of the Structural Form. The proposed methodology was tested in a preliminary study on the façade of a block characteristic of the Southern Commercial Sector in Brasília DF. This sample was built almost simultaneously in the period from 1960 to 1980 and predominantly maintains the characteristics of modern Brazilian architecture at that time, so it has potentially more attributes to be preserved in a renovation process aiming at better energy efficiency. The application allowed analysis that resulted in general guidelines that will allow the future formulation of an indicator for retrofits of the envelope that encompasses the concepts of structural form and energy efficiency.
