A thesis submitted in partial fulfilment of the requirements of Oxford Brookes University for the degree of Doctor of Philosophy

Doutoramento, 2009.

"Worldwide, there is a vast fragile earthen heritage that is barely surviving due to serious damage and decay of the fabric. In general, it is believed that natural agents are the overall cause for failure of earthen heritage. However, when thoroughly evaluating cases of decay, it is discerned that the interventions of conservators have a major impact. (...) This investigation aims to discover reasons for failure of earthen heritage conservation; to identify consistent criteria standards for conservation intervention across identifiable indicators; to give significance to conservation theory in the field of earthen heritage; and to provide a framework concerning intervention strategies in earthen heritage conservation. The research methodology of this investigation is based in qualitative methods and a case study strategy analysing three World Heritage earthen sites : Chan Chan in Peru, Ait Ben Haddou in Morocco and Arg-e Bam in Iran. (...) This research suggests standards for high quality intervention through the definition of criteria for decision-making, indicators of quality and indicators of best practice, as well as clarification concerning procedures in methodology of intervention. It also stresses the importance of conservation theory in earthen heritage conservation, combining theory and practice, as well as defining specific principles. Finally, this investigation recommends an overall strategy in the conservation of earthen heritage, with particular emphasis on an approach that integrates education, awareness and research; anthropological conservation; scientific conservation and preventive conservation".