Building extension

About the new construction from 2015-2017


The facade of the three-storey building was to match that of the existing office building. The two buildings were to be connected. In addition to 45 workstations, new meeting rooms, a kitchen and a large staff meeting room were to be created. Schenk Fleischhaker Architekten from Hamburg, who had also designed the existing building, were commissioned.

Award of contract

Merten Architekten from Hennef Heisterschoß, a regional architectural company, was assigned with the contract award, construction management and supervision. Particular attention was given to promoting sustainability and energy efficiency throughout the entire execution. In contrast to the construction of the previous building, a general contractor was not appointed. Instead, the work was assigned to individual contractors, such as those focused on structural design (statics), building physics (which assess energy efficiency, such as thermal insulation), fire protection, and building services (which encompass ventilation, heating, electrics, etc.).

Heating and ventilation

The facility has underfloor heating supplemented by an air heat pump. This ensures that heat is supplied in a highly efficient manner without having to use unsightly radiators. Additionally, a regulated ventilation system is also in place to ensure the building remains cool on warm summer days. During the day, the indoor climate is improved by the constant exchange of air, without the risk of drafts.


Facade The facade has a classic rendered finish. The windows are dark aluminum with wood trimming, similar to those in the existing building. Some of the larger elements are fully timber framed, further enhancing the appearance.


The entrance is video-monitored. Some areas, such as the benefits department and payments, are now freely accessible only to authorized employees in order to meet data protection requirements.

Important steps

At the start of the construction project, the team faced its first challenge: The building permit took nearly nine months to be approved. While some initial preliminary work and earth excavation was possible, all subsequent work was delayed. Around 30 companies from the region were involved in the project. Two further obstacles emerged at the beginning of 2016. The delivery of the windows was delayed, and complications with the exterior plaster hindered construction progress. As a result, appointments with subsequent tradesmen had to be rescheduled and postponed, causing inconveniences with the involved companies. Shortly before completion, further issues arose with the sewer connection in June 2017. It turned out that the connection was higher than initially expected, and consequently, an additional concrete shaft was required to install a pump and power connection. These events delayed the move by an additional two weeks.

Energy certificate of the new building


January 2014 The neighboring property is purchased
June 2014 The first draft planning is available
June 2014 The building application is submitted
September 15, 2015 Completion of the new parking lot
November 12, 2015 The excavators for the earth excavation roll in
December 14, 2015 The building permit is issued
April 14, 2016 Ceremony
July 2016 Commencement of interior work
August 8, 2017 Construction acceptance of the new building and start of relocation

In figures

Area: 1,300 m² on three floors
Workplaces new building: 45
Workplaces old building: 45
Construction costs: 3 million Euro
Solar system: 21.6 KW peak
Energy efficiency: according to KfW 70