Exterior surfaces of our old towns and architectures, defining the essential of their historical and aesthetic presentation, were executed with local materials using lime arts and techniques. These solutions for exterior façades are being destroyed at an impressive rate and substituted by solutions based on Portland cement.

At interventions on ancient buildings is still current to extract all renders and finishing, whatever the damage type and degree. It happens partially because of incapacity to analyse the situation and lack of knowledge about materials and technologies adequate to their conservation, consolidation and repair.

The study of lime technology, its colours and the techniques used in decorative exterior surfaces has already been started, however it is still lacking the gathering of fundamental ancestral knowledge that has not yet taken place and articulate this with scientific studies that will permit the characterisation of the actually used materials, restoring working technology and application processes.

In synthesis, it is necessary to widen the knowledge in this field, in order to answer the problem of conservation of ancient surfaces: taking an existent surface, decide, with scientific criteria, the strategy to be used: conservation, implying the use of consolidation and restoration technology; punctual repair, using new materials and technologies similar to pre-existent ones; or substitution, requiring the use of compatible materials and technology, in the functional and aesthetic sense.

Articulating multidisciplinary capacities, based on actual needs for the advance of conservation science, this project aims at valuing the re-use of traditional materials and technologies, creating an incentive for the exploitation of endogenous capacities that are almost disappearing and have nowadays economic viability, at the same time as it tries to (re)introduce the most adequate methods and technologies for conservation of authenticity and restoration of our urban and architectural heritage.

This project, with the reference POCI/HEC/57723/2004 is being accomplished atn LNEC (Laboratório Nacional de Engenharia Civil) in Lisbon, Portugal, and is co-financed by FCT (Foundation for Science and Technology).