In Germany, the community of volunteer firefighters plays a key role in dealing with fires, floods and other major incidents. Recently, a new working facility was built for the special community of volunteers in the Hessian town of Caldern. Now, when an emergency call comes in, the firefighters burst out of a sustainable building that is even the proud owner of a DGNB Gold Certificate. It’s also worth mentioning that it was the first time in the history of the DGNB that a firefighting organisation has been through the certification process.
The Caldern Volunteer Fire Department in the borough of Lahntal enjoys a long tradition. Founded in 1933, for many decades the resident volunteers had their own equipment building, but of course eventually the time came when it no longer met the technical and practical requirements of a modern fire station, so the community pulled together to find a new location. The groundbreaking ceremony for the new building took place in August 2019.
Modest but also quite spacious
The job of designing and erecting the new building went to apd, a Frankfurt-based architecture and engineering firm. Its brief for the 5000-square-meter plot, which stands on a hillside, was to construct a compact building with white plaster on the outside and an eye-catching, overhanging canopy. It should be easy to move around quickly inside the building, which now proudly bears an elongated greenified roof. In the event of an emergency, volunteers must be in a position to take to the road immediately.

Crisp contours, minimal use of materials and certified sustainable construction methods – the recipe for a building made to last. © Andreas Ochs und Lars Sehrt
The development kicked off with a hall spanning two levels to house fire engines and ancillary rooms for technical equipment. To the back of the building, visible from the outside through a ventilated wooden façade, are rooms for socialising and training on two levels. These are an important meeting place for the volunteers – somewhere to wind down and enjoy time together after challenging operations. They are also where courses take place and the next generation of volunteers undergoes training.
The first DGNB-certified fire station
“The idea of gaining certification only came up during the planning phase,” recalls Marcus Ochs, who was responsible for managing the project at apd. “It didn’t take much to convince local politicians or the development department. Before we knew it, they came back with a thumbs-up. There was a bit more hesitance from the other parties involved in the planning process at first, and from the craftsmen, so at the beginning a lot of clarifying had to be done to explain how the DGNB certification system works. But looking back, everyone saw the benefits, especially given that the additional outlays were quite reasonable.” Ochs, who also heads up the Caldern Volunteer Fire Department, was able to contribute to the project with his expertise on two fronts – not just as a firefighter but also as an architect.

© Andreas Ochs und Lars Sehrt
His colleague Christopher Seifert, a trained DGNB Auditor, ensured the building met all the right sustainability criteria to adhere to certification requirements. He had also already surmised that the plans drafted by Ochs would be suitable for certification. One particular challenge with the development was that until then, out of more than 7000 DGNB-certified buildings none could be described as a fire station. After careful coordination and discussion, the DGNB criteria were therefore adapted so they were also applicable to this project. Gaining DGNB Gold Certification proves that their efforts were worthwhile – and the endeavour of validating the sustainability of the building was achieved.
It was also the first time the borough of Lahntal had received DGNB certification for any building. “Our community feels that it bears an explicit responsibility to set a good example to others, and, in so doing, make our own contributions to sustainability,” says Sandra Riehl, head of the municipal building department in Lahntal. “We’re actually a little bit proud that we have such a visually appealing building – and that it achieved excellent sustainability scores. Our aim was to get silver, but in the end it was even given a gold award.”
Sustainability across the board
The energy concept revolves around an air-to-water heat pump in combination with underfloor heating. This enables heat extracted from the surroundings to be exchanged with the heating system, which can also run on low supply temperatures due to the expansive surface area. In addition, emphasis was placed on environmentally and socially responsible materials.
Last but not least, the users of the building were involved in the project. The volunteers were divided into twenty task forces, which erected and financed some parts of the building themselves. A voluntary scheme has also been set up for certain housekeeping duties. This has fostered a sense of identification with the new building among the volunteers – ideal for running a long-lasting and thus sustainable building.

Marcus Ochs (apd architektur+ingenieurbüro), Manfred Apell (Bürgermeister), Sandra Riehl (Bauamtsleiterin), Rafal T. Rogalski (apd architektur+ingenieurbüro), Johannes Kreißig (DGNB) (f.l.t.r.). © DGNB
Determination, enthusiasm and cohesion – the ingredients of success
The fire station entered operation – as planned – in May 2021. It is currently used by 35 active firefighters, who feel just at home in their new workplace as the next generation of junior volunteers. Because everyone played their part in the success of the building, all have their very own anecdotes to share.
“It was wonderful, but projects like this only come together if local politicians, the authorities, the architects, the craftsmen and future users of the building work in unison and pursue the same goal. Everyone involved in the project can be proud of what’s been achieved – and quite rightly so. Especially the volunteer firefighters. They’ve had to wait two decades to finally move into suitable new facilities,” recalls Marcus Ochs, a firefighter himself in Caldern and the project manager.

Based on a compact structure, the building is integrated into the local topography. © Andreas Ochs und Lars Sehrt