Summary In the doctoral thesis at hand existing sustainability assessment schemes are presented, analysed and compared with each other. On the basis of existing systems and the results of the comparison an economical-ecological assessment system is being developed focusing on the refurbishment of buildings using traditional building principles. Beside traditional building principles such as the utilisation of clay, the integration of old techniques of crafts, intelligent building architecture for heating and cooling etc. modern and efficient building technologies are considered as well of course. In the thesis sustainable or ecological building respectively is identified as a crucial measurement in the framework of the protection of the climate. Furthermore, possible areas of integrating such principles in the refurbishment of existing buildings are described. Traditional building principles from all over the world are presented and common principles offering advantages for the refurbishment as well as for the construction of new buildings are named. With a comparative analysis and cirital review of existing assessment schemes for sustainable building being in use in the United Kingdom, the United States of America, Japan, Canada, Australia and as of 2009 in Germany as well criteria are developed being important for a system focussing on existing buildings and in which traditional building principles are relevant as well. At the end of the day the overall target of such an assessment scheme is to inform planners, house owners, and other stakeholders involved in the building process by the means of an instrument that illustrates the possibility of an increase of resource efficiency while at the same time a refurbishment that protects the existing construction. Research questions being dealt with implicitly and explicitly are listed in the following: Applying principals and methods of traditional building and the use of traditional building material can improve resource productivity and the overall sustainability of buildings. Existing buildings require a specific accuracy in case of refurbishment due to the complex interrelations concerning the exchange of warmth and moisture inside the building, especially when the building is retrofit in terms of its energetic efficiency. Traditional building can strengthen regional economies through the assignment of local craftsmen. Assessment schemes are able to improve the knowledge of house owners concerning advantages and disadvantages of traditional building. As such the application of traditional building can be fostered and damages at buildings can be avoided. There a comparable opportunities of traditional building in international context. Most new buildings are built according to modern architecture and are therefore similar concerning the construction as well as the used materials independent from the climatic zone they are located in. Traditional building principles and materials may improve resource productivity as a construction method being better adapted to the respective climatic conditions. The building of new houses in thorough accordance with building tradition is not desirable as the requirements of modern house owners are considerably higher, and in many cases the building legislation is restricting this.