Subtask 1 investigated the possibilities and limitations of common data bases and monitoring systems. This subtask is strongly related to subtasks 2 and 3 by linking the available input data – as much as possible based on existing (non-intrusive) monitoring systems and data bases – to the accuracy of the predicted outcome. A state of the art survey of existing methods, their costs, timeframe and typical accuracy was made. In a second part the step from monitoring to current on board measuring methods was reviewed. Finally, the application of an on-site measured heat transfer coefficient within the global energy efficiency framework was proposed
