**2.2 The current standards of habitability of housing in Chile**

The regulation of building standards in Chile arose in 1992 with Decree No. 47 that created the General Code of Urbanism and Constructions [7]. The first topics that were regularized through this document were the fire resistance standards of buildings and the requirements for sewage and rainwater systems. Then, in the year 2000, the first stage of prescriptive Thermal envelope regulations for housing was added to the General Code, to establish a minimum insulation standard for the roof of the dwelling, according to the climatic zone of the country.

Then, in 2007, the second stage of prescriptive Thermal envelope regulation expanded the requirements to other building components, such as exterior walls, ventilated floors, and windows of the dwellings.

A third stage of the Thermal envelope Regulation is pending, however, it is known that it will consist of an adjustment and reduction of the prescriptive U-Value of some of the building components, for some of the climatic zones of the country. These adjustments have already been applied on a mandatory basis for new homes in cities of Chile that currently have Atmospheric Decontamination Plans (PDA), as well as in a voluntary way, through the Certification System for Sustainable Housing [6].

The following **Table 1** presents a comparison between the current thermal envelope standards of the Chilean Regulation and the thermal envelope standards from the Certification System for Sustainable Housing in Chile:
