A performance hall fills former bathhouse
Completed in 1895, the Imperial Spa in Karlovy Vary stands as a symbolic achievement of its era, combining architectural and spa technologies. The spirit of the late 19th century—an age that saw the invention of the light bulb, induction motor, telephone, internal combustion car, and airship—was reflected in its design. Architects Ferdinand Fellner and Hermann Helmer introduced a system for processing and distributing peat, using conveyors and elevators to deliver fuel to bath facilities spread across multiple floors. Thanks to this efficient design, up to 2,000 visitors could use 100 bathtubs simultaneously each day.
The Imperial Spa thrived for decades but gradually fell into decline as it strayed from its original purpose. By the late 20th and early 21st centuries, it occasionally hosted cultural events, but even those opportunities dwindled, leaving the building neglected. The search for a meaningful new role—one that could justify the high cost of restoration—led to its transformation into a cultural venue. The former machine room, once filled with conveyors transporting peat, has been reborn as an atrium housing a concert hall and multipurpose spaces. Where time once seemed frozen, the Imperial Spa now tells new stories centered on culture and the arts.
Inspired by the historic ‘peat machines,’ another kind of mechanism has been introduced: advanced stage and acoustic technology. The hall adapts to the character of each performance, with systems that adjust spatial and acoustic conditions. Reverberation time, sound direction, and intensity can all be fine-tuned. An orchestra shell is fitted with movable panels that reflect sound toward the audience. Triangular panels above the stage rotate to provide reflection, absorption, diffusion, or focusing, while wooden floor panels act as resonating plates, amplifying the instruments’ tones. The hall supports a wide range of events—from classical concerts to theater, dance, conferences, film screenings, and popular music. Heavy blackout curtains can transform the space into a dark, acoustically isolated venue, while stage and sound equipment are seamlessly integrated into the building’s structure. Ventilation and fire safety systems are discreetly concealed within the central stair block to minimize visual disruption.
The construction process was highly complex. Because large components could not be brought into the atrium, every element had to be hoisted through roof openings in smaller units and assembled on site.
The Imperial Spa has thus been reborn—drawing inspiration from its industrial past while embracing today’s cultural technologies. Balancing preservation with innovation, it represents a model example of reinterpreting historical heritage for contemporary life through architecture, technology, and culture.
Project: Concert Hall in the Imperial Spa in Karlovy Vary / Location: Mariánskolázeňská 306/2, 360 01 Karlovy Vary, Czechia / Architect: Petr Hájek ARCHITEKTI / Author / Lead architects: Petr Hájek, Nikoleta Slováková, Martin Stoss / Cooperation: Petr Vlček, Martin Vondrášek / AVT Group (Acoustic Design and Audiovisual Technology), Robert Nos, Martin Matoušek / GRADIOR TECH (Structural Steelwork and Mechanical Technologies) / Client: Karlovy Vary Region / Courtyard Area: 492m2 / Enclosed Volume: 9,000m3 / Project year: 2019-2021 / Completion: 2023 (Trial Operation), 2024 (Scheduled Completion and Commissioning) / Photograph: ©Benedikt Markel (courtesy of the architect), ©Petr Polák (courtesy of the architect), ©Ester Havlová (courtesy of the architect), ©Pavel Nasadil (courtesy of the architect), ©Petr Hajek (courtesy of the architect)
