Stage renovation of the Hus Church building by architect Janák

Motto: "...the architect's work will be best if it is not visible that the monument has been returned to life...."
(Pavel Janák: Architect and monument, 1952)

The building of the Hus Church was one of Janák's last realizations of large-scale architecture. Today, it is a significant monument of functionalist architecture of both Czech and global importance and a cultural heritage site listed in the register of cultural monuments of the Czech Republic. "An extremely thoughtful composition of three basic elements - the ceremonial hall, the residential house, and the belfry can surprise us at every turn with shifting configurations of forms, the play of cast shadows on white surfaces, and unexpected vistas. Nevertheless, the scientific-functional nature of the building is emphasized by the factory shed lighting of the ceremonial hall, the factory glass block strips on its base, and the constructivist skeleton of the belfry, reminiscent of the structures of water reservoirs in factories or at train stations." (Rostislav Švácha, From Modernity to Functionalism, 1994).
In 1998, we, as architects, were given the opportunity to participate in the development of the future restoration of the building. Aware of the real need for the extent of repairs, which differed financially by orders of magnitude from the volume of work previously carried out, we prepared a comprehensive concept, established a sequence of urgency for individual repairs, and created stages according to construction continuity. We developed a framework project and, along with the Council of Elders of the Czechoslovak Hussite Church, began to seek financial resources from potential funding agencies. The change in the owner's approach, the Czechoslovak Hussite Church, along with the existence of a concept and project, received a response from funding institutions, and in 1999 it became possible to initiate the first stage of restoration. However, despite the increased support from funding institutions, it was and will continue to be necessary to divide the restoration into a series of smaller stages, corresponding to the possible financial volumes each year. Despite partial success, that is, the possibility of starting the overall restoration at all, the overall approach to the restoration of the monument was influenced by the limited amount of funds. Therefore, we chose methods that are a compromise between carrying out the maximum possible extent of modifications from limited financial resources and achieving results commensurate with the significance of the building.
The first stages of restoration included roof repairs, followed by façades and modifications of exterior elements and the adjustment of the church's interior. The remaining interior modifications (columbarium), the tower, the interiors of the residential part, and repairs of internal installations will remain for further stages.
The original façades, executed in the manner typical of the time of construction and characteristic of functionalist buildings, using scratched brizolit with mica grains, were compromised by the influences of rainwater infiltration, capillary rise of water from the subsoil, and primarily by the condensation of water vapor under the plaster and the subsequent freezing and destruction of entire layers of exterior plaster. The aim of the proposed reconstruction of the façades was to restore the original appearance and character of the plaster and to eliminate factors that would cause subsequent destruction of the new plaster, namely primarily removing the condensation of water vapor in the structure. The most suitable technology chosen involved the use of an atypical insulation system composed of a combination of thick-layer scratched plaster with mica grains and colored stones in the composition according to the original plaster and glued, densely anchored thermal insulation boards.
The flat roofs of the building were constructed with an inverted assembly of layers. The roof of the residential part and the terraces were finished with a replica of the original terrace pavement by architect Janák, remnants of which were found. The original gray on the roof of the prayer house, sprayed with puro coatings and covered with asphalt membranes, were restored and fitted with titanium-zinc cladding.
The goals of the detail reconstruction were:

1. to restore the color and surface texture of the preserved elements,
2. to remove additional utilitarian modifications and elements,
3. to locate and re-install dismounted original elements,
4. to execute new elements in the spirit of the original forms using simple geometric shapes with minimal expressive means and traditional materials.

Before the start of the reconstruction of the church's interior, a historical construction survey of the original coloration from the time of the church's construction was conducted, and a computer animation of the original interior coloration was developed. The aim of the color reconstruction was to restore the original state. A problem with returning authentic colors lies in the existing sculptural decor of the interior, three plastic reliefs by sculptor Znoj, added to the interior later without cooperation with architect Janák and out of context with his architecture. Due to the strong coloration of these reliefs, it was necessary to adjust the color shades so that they did not conflict with the reliefs. The original division of colors of surfaces according to tectonics was strictly preserved. The principle of lighting the church was restored according to the original concept of gradually replacing natural light with artificial light from the same directions. Functional stage lighting was strengthened while adhering to the same principle.