With the implementation of directive 2002/91/EC on energy performance issues have arisen on the complex set of problems that hold between energy efficiency and preservation perspective. The aim of this paper is to describe the state of art in Swedish sustainability regarding energy efficiency and integrated conservation and how these have been carried out in our built heritage represented by the regional co-operation project the Halland Model where case studies are performed. The aim of EEPOCH, Energy Efficiency and Preservation in Our Cultural Heritage;- Through generic research the case studies form a foundation for a theoretical model directed on application for integrated balancing of energy and preservation demands without diminishing intangible values in our built heritage. - The qualitative research part includes interviews for analysis on communication between different occupational cultures to illuminate methods within and between connected professions, especially their interdisciplinary approach.