Blaibach is a village in the German state of Bavaria, near the border with the Czech Republic. Like other communities in the region, it faces a declining population and an increasingly vacant town center as people leave the area for the lure of larger and more modern cities. Enter a government revitalization program, and Munich-based architect Peter Haimerl, who has remade Blaibach into a cultural magnet with a new concert hall that, at 200 seats, can hold fully one-tenth of the town's population. But visitors looking for the concert hall might have to look twice: For fear of overwhelming the village square, Haimerl placed the bulk of the building below grade, save for a tilted, cubic granite block (which contains the upper rows of seats) that projects from the ground plane. To that end, "the concert hall itself is a sculpture," Haimerl says. The architect selected a specific cut of rough granite to clad the volume because "the old houses in Blaibach were all built from this material," he says.

Concrete Structure

A concrete staircase on the exposed underside of the tilted block leads to a subterranean lobby, which features a bar, coat check, and restrooms beneath a wood ceiling plane. But the main event is the concert hall itself: an entirely concrete space that is acoustically fine-tuned for classical music. "Concrete is the best material for good acoustics," Haimerl says. "What you need is a very hard surface, and a few areas where you dampen the sound. People are using wood, but it is not the best material because it is not stiff." The concrete here is a lightweight mix with recycled glass aggregate that results in a rough textured surface "like paper," the architect says.

Acoustics

Haimerl's team worked with acousticians to determine the ideal shape to best modulate sound, which resulted in a pleated ceiling and walls. Working with an automotive fabrication team to execute the delicate formwork, Haimerl oversaw the process to pour the concrete in place, with tubing for radiant heating, LED light fixtures, and other utilities embedded directly within. At their deepest point, Haimerl says, the walls measure 60 centimeters thick, and at the most delicate edges of the pleats, the concrete is as thin as 5 centimeters. Another set of tubes in the concrete help to modulate the bass tones, resulting in a balanced acoustic experience.