What projects are you working on at the moment?
We are involved in a German research program called Energy-optimised Construction. It funds monitoring of buildings. Together with two partner universities our research group has been collecting all data from the different monitoring projects since 1997. We are doing comparative analysis, putting together results, benchmarking buildings and also communicating the results to the public and to interested planners. So far 70 new and renovated buildings have been monitored.
We are also working on adaptive comfort models in a three year project, where we study adaptation mechanisms of occupants in buildings in more detail. We will simulate a two room office space in a climate chamber and expose between 50-60 individuals to different conditions. They will for example be allowed to change the indoor conditions or be exposed to a fix indoor temperature, while we measure parameters such as heart and sweat rate and let them fill in questionnaires. We have conducted the project for one year, but we need more data to develop a more realistic behaviour model of occupants. Today there are only very simple models of occupants. As a part of this project, we also do surveys in real offices.

What result has surprised you the most in the research program?
Although these buildings have been involved in a research program meaning everybody was very ambitious to reach a high energy target, one big surprise was that there is still a remarkable gap of up to 30 percent between the planned energy consumption and the real energy consumption. That was an incentive for further research on monitoring software and techniques and management systems. We started developing data visualisation software, which will be available at the end of next year. This is software that basically consists of a huge database. Monitored building data are collected over longer periods and presented graphically to visualise the energy performance of the buildings.

What is especially challenging during the design of energy efficient buildings?
A big challenge is to have a continuous flow of relevant information about energy efficiency throughout the whole design, planning and building process. The building owner, the architect and the energy expert are very motivated in the beginning of the project. Then more partners come into the team and the flux of information about energy efficiency is not necessarily consistent until the building is finished.