This report summarizes part of the work of IEA-ECBCS Annex 47 Cost-Effective Commissioning of Existing and Low Energy Buildings. It is based on the research findings from the participating countries. The publication is an official Annex report. Report 1, Commissioning Overview can be considered as an introduction to the commissioning process. Report 2, Commissioning Tools for Existing and Low Energy Buildings provides general information on the use of tools to enhance the commissioning of low energy and existing buildings, summarizes the specifications for tools developed in the Annex and presents building case studies. Report 3, Commissioning Cost Benefit and Persistence presents a collection of data that would be of use in promoting commissioning of new and existing buildings and defines methods for determining costs, benefits, and persistence of commissioning, The report also highlights national differences in the definition of commissioning. Report 4, Flowcharts and Data Models for Initial Commissioning of Advanced and Low Energy Building Systems provides a state of the art description of the use of flow charts and data models in the practice and research of initial commissioning of advanced and low energy building systems. In many countries, commissioning is still an emerging activity and in all countries, advances are needed for greater formalization and standardization. We hope that this report will be useful to promote best practices, to advance its development and to serve as the basis of further research in this growing field."