Nowadays, the question of heating costs for new residential buildings is often a central matter. For office buildings, high quality of the workplace is normally of main importance, along with the consideration of cooling the building. This does not mean, however, that the construction costs and follow-up have to be high. For office buildings too, energy-optimisation does not just lead to low operating costs but also provides a high level of interior comfort. In Aachen, the concept of a solar housing estate induced its planners to fulfil the same energy requirements for their own new neighbouring office building. In addition, the building was supposed to be particularly economical to create and run.

In the concept phase, the costs that are expected over the entire construction and usage period were broken down completely, evaluated and optimised. The more expensive planning process beforehand is paying off -  low follow up costs and highly flexible usage promise to secure the investment in the long term. Since, in this case, the contractors planned and are also now using the building themselves, they all acted in concert. The integral planning approach, a basic requirement for a sustainable, energy-efficient concept, was considerably easier to perform compared to other projects.
The spacious floor plan without load-bearing interior walls allow the building to be sub-divided variably into different units and various office shapes.

The energy concept which relies primarily on the use of geothermal heat or cooling in conjunction with a heat pump is kept simple. The integration of the building services equipment into the ceiling or floor offers much flexibility for how to use the interior space. From the very beginning, the office building in Aachen was meant to be more than a one-off experiment. The concept is to be converted into a “product series” so that planning costs are reduced and the experience gained previously can be benefited from.
The office has been in use since summer 2002. A subsequent monitoring process was sponsored by the German Federal Ministry of Economics and Technology in the scope of the key research area, EnOB - "Energy-Optimised Construction". Evaluating several hundred measurement points over a five-year period has played a decisive role in ensuring that the building can now produce such good characteristic value. The evaluation will therefore be continued.