The building envelope in the rehabilitation of affordable housing estates

This paper studies the rehabilitation of the residential building envelope in urban affordable housing estates built between the forties and the seventies of the twentieth century. The state and functioning of the envelope of this vulnerable building condition its stability, habitability, energy efficiency and architectural identity, with its effect on the balanced development of the city. The research is carried out by assessing one of the first urban rehabilitations that have been completed in Spain, in the Poblado Dirigido de Cano Roto, Madrid, between 1994 and 2004. The methodology used raises a detailed qualitative and quantitative analysis of the functional adequacy of the thermal envelope prior to rehabilitation, which results in a diagnosis, and at the current time, which allows an evaluation. Both states are structured in a study of the enclosure structured in the roof, facade and floor, according to the definition of thermal envelope issued by the Spanish Technical Building Code (Codigo Tecnico de la Edificacion) and applying its scales to obtain an objective and current evaluation. The systematic study of the envelope improvement confirms that the rehabilitation process has achieved optimal parameters, which contribute to the renovation of the urban housing stock, but it implies the alteration of its image with the consequent loss of heritage value or architectural interest. This result leads to question the guidelines and principles of these operations, and the need of their own regulations.