The principal objective of this research project is to set up a holistic approach for treating existing historical structures, specifically focusing on gaining an improved understanding of the behaviour of historical structures under load effects and environmental exposure conditions; development of effective in-situ non-destructive investigation and monitoring techniques; development of assessment and analysis tools and development of models for lifetime expectancy.The project will develop a Damage Catalogue that describes typical degradation forms and procedures of historical structures as well as new, effective methods for diagnosing the condition of historical structures and suitable techniques for the monitoring of the damage evolution of historical structures and a systematic algorithm for the prediction of their operational lifetime. The results of the project will be introduced into routine practice for all target groups and form a basis for the development of teaching materials at both partner institutions. Achievements: Conserving historical buildings in an as energy effi cient way as possible, the evaluation of their state and their life expectancy, as well as fi nding new ways and possibilities for its prolongation has become essential in European practise and also in Hungary and in Croatia. Within the project a new methodology was developed for the precise analytic work on the buildings and guidelines were developed for the application of the procedures for accurate evaluation and lifeexpectancy prediction of historic buildings, with special focus on those built in stone and brick.