3rd prize DOMIGIUS 2021 – Pirach water tower

• Projekt
  Wasserturm Pirach

• Architekt
  brüderl Architektur GmbH

• Bauherr
  Brüderl Vision GmbH

• Produkt
  750 m² Planum-Fassade

• Verarbeiter
  Spenglerei Langwieder

• Fotos
  © Manuel Hollenbach, Bildrechte: brüderl.

With its distinct cylindrical silhouette and a picturesque silver-colored metal facade, the former water tower of Pirach makes an architectural statement in the hilly landscape of the Traunreuter Alpenvorland. Inside the striking building, a total renovation created living and exhibition spaces that reflect a high level of design sophistication in the interior finishes.

Until the end of the 1960s, the tower tank, which was only 10 years old at the time and had a capacity of around 250,000 liters, secured the water supply for the surrounding villages. After the switch to pumped storage plants, the 30-meter-high water tower – despite its imposing shape – initially led a forgotten existence. Later, it was converted into a massive support for mobile phone antennas. However, this was not to the delight of local residents, who successfully protested against a planned extension of this function.

To get rid of the maintenance costs, the city of Traunreut put the property, which was not particularly attractive at the time, up for sale six years ago. In retrospect, it was a good thing that decades ago the young boy Schorsch Brüderl had climbed the tower on a school trip and enjoyed the fantastic panoramic view from the very top. Over the years, he watched the sad development of the disused building with an alert eye and increasingly saw it as an “object of secret desire” for himself. In the meantime, he had advanced to become a successful entrepreneur, and when he was offered the building for sale, he quickly decided to put it to good use again.

At the end of a long conceptual phase, the new owner agreed with the critical approval authorities on a mixed use, which included the construction of a new three-story annex. With dark wooden facades, this cube hardly appears visually. Today, the first two floors house a spacious private apartment. On the second floor, a tastefully furnished apartment invites vacationers to spend their vacations with a view of the Alps. All floors above serve as a showcase for the Brüderl Group’s achievements and as a world of experience for the exquisite furnishings produced by the company’s own furniture factory.

It is important to know that the Brüderl brand is based on diversified companies whose activities are closely interlinked. The range of services extends from project development to architecture and interior design services to turnkey construction including subsequent building management. The fact that the beginnings go back to a furniture carpenter’s workshop is revealed by the manufactory, which advertises a “beautiful ambience”. Individual one-offs are just as much a part of its range as series products and complete interior fittings.

Refurbishment with surprise effects

Giving the landmarked water tower its new functions was literally a rocky road. Not only because it was originally built as a solitaire in the rural surroundings, but is now surrounded by residential buildings – with neighborly skepticism to resistance included.

First of all, it is undoubtedly a particularly tricky task to plan a generous apartment floor plan into an obligatory round perimeter, which also has a very modest number of windows. The bathrooms, bedrooms, adjoining rooms and kitchens on the living floors are cleverly integrated into the circular structure. The living areas are oriented towards the extension, which offers a fantastic view over the hilly landscape of the Chiemgau and the Alps thanks to the complete glazing of its front wall. Parallel to this, the abundant daylight reaches deep into the round building.

The structural challenge of the renovation task turned out to be just as massive as the mass of the exterior walls. Proudly 80 centimeters thick at the base, the masonry of small-format bricks tapers to around 35 centimeters at the eaves. Because the work was carried out on comparatively shaky scaffolding at the time and, moreover, there was no laser measurement, the tolerances in the circular area are quite generous, both inside and out. As if that were not enough, the diameter of the tower also tapers by around 70 centimeters to its full height. For the conceptual design and production of the exterior façade, these found basic conditions concentrated into a highly exciting task.

At great expense, the interior of the tower was first restored to its shell condition. All of the interior walls were dismantled and new walls were built using dry construction methods. The biggest chunk was the removal and securing of the outer wall over three floors in the area of the extension connection. In the segmental arch, which was opened to a width of around 5 meters, a round steel column inserted in the center now takes over the load transfer from the diameter-wide spanned slabs and the masonry above. In contrast, the partial enlargement of windows and interior reveals was a rather modest job.

The renewal of the entire building technology was carried out under the premises of hygiene, modern comfort and energy efficiency. The latter was especially true for the heating technology, which had to be adapted to special room climatic conditions.

Facade turned in a circle

How strongly wind and weather affect the exposed tower facade, had been shown by the badly strained exterior plaster. But the aspect of weather protection was not the only concern of the purposeful client. He also wanted to visually enhance the landmark, which is visible from afar over 360 degrees – in other words, to give “the aged masonry” more luster, which is what ultimately happened.

Facade options were examined, varied and rejected, from ETICS to standing seam cladding – as is the case today with the roof – and finally to the rear-ventilated metal facade. An adequate partner in terms of product range and professional design including detailed planning was found in the Upper Austrian company DOMICO. Flat surfaces that follow the curvature in segments, plus a non-penetrating fastening of the elements, were the decisive structural engineering arguments in favor of the Planum façade. The fact that it also copes with the sometimes heavy tolerance compensation by means of its flexible substructure also spoke in favor of the decision. Last but not least, the jointly developed façade solution enabled accurate integration of the windows in terms of both craftsmanship and design, regardless of whether they were positioned within the segment area, at its edge or even across segments. A round thing, then, on the facade round.

Once the feasibility had been clarified, the next step was the design: How to bring the square to the round in a pleasing way? How to give the tower a striking, but by no means dominating, long-distance effect? It was clear that the diameter of around 10 meters necessitated segmentation, as did the tower body, which tapers conically upwards to around 30 meters. So it was a matter of well-founded planning, trial and error, and adjustment. In the end, the optimum segment lacing resulted in the division into 20 sub-segments of equal width horizontally and 11 gradations vertically. A variation in the segment height emphasizes the base including the entrance on the ground floor. The tall windows at the top of the tower, reminiscent of a lighthouse ambulatory, also resulted in a height differentiation of the two upper rows of segments. All segments in between are identical in height.

After tightening the metrological conditions, the surface and architecture of the façade were at issue. The arrangement of the uniformly 60-centimeter-wide individual planum elements was examined: horizontal or vertical variants, plus different colors and structures, starting with the solid color and ending with a sequence or mixture in the surface. Furthermore, an accentuation of the element and shadow joints was under discussion, as well as the accentuation of the horizontal Z-folds with minimized drip edge.

In the end, it was the simple solution that convinced. The 1.25 millimeter thick planum elements were executed in the color white aluminum, RAL 9006, which was also adopted for all visible accessories. The different reflections and the permanent interplay of light and shadow in the course of the day give the tower a playful liveliness and lightness. Moreover, a very special feature makes one forget all the previously considered design variants. It is the horizontally offset elements that visually suggest a rotational movement in the distance. It’s as if the drabness of yesteryear were proudly spiraling up into the sky in a shiny new guise.