The art of transformation

The Story of How the Zenger Transformer Station Became Kunsthalle Praha

Architects often say that the greatest challenge when renovating or converting a building is to preserve the valuable historical essence – the DNA of the original location. How did the Zenger Transformer Station’s conversion into Kunsthalle Praha fare in this regard? The specific genius loci of this site combines a fascinating story and the spatial ingenuity of a technological landmark with today’s need to look at, and think about, the future of society, art, and culture. But any final assessment is up to you – in the meantime, delve into the true story of how an industrial palace of electricity became a living location for art and dialogue in all of its beauty, complexity, and fascinating detail.

A Brief Journey through the History of the Zenger Transformer Station

  • 1779–1930: The site was home to the Bruska Barracks, where Švejk went to borrow money in Jaroslav Hašek’s classic novel: “If we had some genuine nut liquor here, that would fix my stomach. Captain Šnábl in Bruska has such a nut liquor,” says the military chaplain in The Good Soldier Švejk.
     

  • 1897: On 1 September, the Electricity Works of the Royal City of Prague launched its activities. During the interwar period, this was the largest company in the city and employed more than 5,000 people. It was headed by Eustach Mölzer, a progressive individual who strived to achieve technological and social progress across the metropolis. One example stands for all: during the very problematic housing crisis between the two world wars, when individual households did not even have their own bathrooms, Mölzer commissioned the construction of portable housing units and also had a functional bathhouse built in the main building of the transport companies on Vltavská Street.
     

  • Early 1920s: The first efforts were made to build a transformer station in Prague’s Klárov quarter. The situation was complicated. At that time, this was a highly built-up area, with various structures crowded next to each other. In the direction towards the Vltava River, the area was occupied my military warehouses while massive fortification walls extended in the other direction. If a place were to be found for a transformer station, demolition would have to take place.
     

  • 1924: Originally, the space in an unnamed park (across from today’s Kunsthalle Praha) was occupied by a lime kiln, which later was used as a military warehouse. It was demolished in 1924 and was to be replaced by a new transformer station. However, after the warehouse had been razed to the ground, the architects and planners realised that the newly vacated space offered an exclusive view of Prague Castle and the Church of Saint Nicholas. Soon a new design was produced by the architects Vilém Kvasnička and Jan Mayer, both students of Jan Kotěra, and the projects they designed include the Hospital Na Františku in Prague 1. They proposed that a lookout terrace with a balustrade decorated with historical statues be built in the central section of a fairly large building. However, this interesting idea ultimately had to be set aside. The opposite side of the street – dominated by the Bruska Barracks, which were housed in a former Renaissance palace – proved to be a suitable alternative and a final decision was made. Demolition activities started once again, and a historical gem was levelled.
     

  • 1928: Independently of each other, the architects Vilém Kvasnička and Josef Štěpánek each proposed a Functionalist transformer station for the newly selected site. To this day, Josef Štěpánek remains an exceptionally talented, albeit somewhat tragic, figure of Czech architectural history. At that time, his vision of a transformer station was conceived as a layered Functionalist gem. Proponents of avant-garde architecture raved about the design, but it was too radical for the historical morphology of Prague’s Lesser Town and so could not be used.
     

  • 1929: Now on his own, Kvasnička submitted another design for the transformer station, this time in Classicist style, and it met all of the requirements. Although the building’s exterior was an example of modern Classicism so that it fit in will the other buildings in Lesser town, the interior was conceived as a modern reinforced concrete space. Taking into account the definition of modern architecture as interpreted by the Swiss architect and theorist Le Corbusiere, it is clear that Kvasnička’s design was in harmony with many of its principles – from the flat roof extending over the columns in the side street that raise the structure to the open-design layout. In many respects, this was a modern structure that is internally adapted for industrial operations, but externally still looks almost like an urban palace.
     

  • The station is named after the famous physicist and meteorologist Václav Karel Bedřich Zenger, a professor at Czech Technical University in Prague. Among other things, Zenger advised Gustav Eiffel on how to properly install a lightning rod on the Eiffel Tower in Paris.
     

  • 1930: On 15 January, construction began on the Zenger Transformer Station. The City of Prague also issued a permit for blasting away a part of the Letná massif and the surrounding shale rocks with dynamite.
     

  • 1931: The switching station was brought into operation.
     

  • 1932: The Zenger Transformer Station officially launched activities, including the operation of the converter station in Klárov, which replaced three older structures: the converter station in Lesser Town, the one at the foot of the castle stairs in Klarov, and the Strakovka switching station. In that same year, the Electricity Works took over the Petřín funicular in order to transport visitors and participants to Strahov stadium for the 9th All-Sokol Gathering held from 3 to 6 July 1932. The Zenger Transformer Station became a key node. The technical solution was at a very advanced technological level for that time, and the station transformed high-voltage electricity to low-voltage and also converted alternating current to direct current for tram and trolley bus lines in Prague 6, Prague 7, and a part of Prague 1.

  • 1934: On 10 February, the building was officially inaugurated.
     

  • 1937: The World’s Fair is held in Paris. On display in the Czechoslovak Pavilion are four light kinetic structures, which Zdeněk Pešánek, a visionary of kinetic art, designed between 1932 and 1836 for the main façade of the Zenger Transformer Station. The objects, made of plaster, metal, and plastic, with embedded neon tubes (which were intended to effectively illuminate the Zenger building) were a part of the thematic series 100 Years of Electricity and received an award at the exhibition. However, after they were returned to Prague, they were irretrievably lost during World War II. The models for them are now a part of the collections at the National Gallery Prague.
     

  • 1942: The Electricity Works were shut down and the various divisions were combined under the city-owned Prague General Gas and Water Company, leading to the establishment of Prague Municipal Works.
     

  • 1951: The Zenger Transformer Station becomes the property of the Prague Energy and Distribution Works, while its switching station is transferred into the ownership of the Prague Transport Company.
     

  • 1970–71: The switching station in Klárov underwent significant renovation.
     

  • 1973–1978: The Malostranská metro station was built.
     

  • 2006: All of the technical equipment from the switching station and the breakout station were moved to the basement area of the Zenger Transformer Station. All that remained on the ground floor was the Prague Transport Company’s switching station.
     

  • 2007: The Zenger Transformer Station building became private property. It’s new owner, the company Marvikven, a. s., planned to convert it to a hotel.
     

  • 2011: The architects David Pavlišta and Martin Rajniš (who was also the head architect for the planned hotel), opened their architectural firm in the former transformer station. In addition, they came up with the idea to also use the building for cultural purposes.
     

  • 2012–2015: The underground club Kokpit Kafé operated in the building, where it organised concerts, film screenings, theatre performances, and exhibitions. Over time, the building irrecoverably deteriorated. The risk that the load-bearing constructions made of less durable high-alumina concrete would collapse became increasingly higher. In addition, the dismal state of the technical aspects of the building was intensified by the heavy contamination of the constructions by petroleum oils and mercury, which was the result of the original technologies that were used as well as by irresponsible operations. The Kokpit gradually moved its multicultural evets to the cellar spaces and then in June 2015 stopped them completely.

  • 2015: In February, the building was purchased by The Pudil Family Foundation established by Pavlína and Petr Pudil. In April, the building was declared a cultural landmark at the initiative of the Club for Old Prague. That same year also saw the relocation and comprehensive replacement of the switching station in Klárov and the end of its operation on the ground floor of the Zenger Transformer Station. Because of these changes, the ground floor was entirely vacated of operational technology.
     

  • The aim of The Pudil Family Foundation has been to develop a modern space for modern and contemporary art in the former technical building. The radical reconstruction of the former transformer station was launched under the leadership of the Schindler Seko architect studio with an effort to retain the original genius loci. The thorough conversion has been planned with the intent of preserving important historical elements as well as with the definitive removal of dangerous chemically-contaminated areas. The main priority is to return the building to the public in a condition that is maximally environmentally safe both inside the building and in its immediate surroundings.
     

  • 2022: Kunsthalle Praha, a new space for art, culture, and dialogue, will open to the public on 22 February 2022.

An Electrifying Past and Present 

The year is 2015. It is now definite that the historical transformer station will not become a hotel. Discussions with technical experts and the preservation authorities are proceeding full speed ahead. Our objective is to work together to find a way of preserving as much of the original building as possible, including all of the protected landmark elements of the façade, roof trussing, and various objects of interior ornamentation. All of the basic elements from the original construction will be retained – from the roof covering and eaves, including all of the cornices, façades, underpinning, and steel shutters, and ending with the balustrade of the original “false” terrace and the original staircase. In addition, the remnants of copper electric wiring from the technical history of the Zenger building are an inseparable part of the black and bronze floor in the café on the third floor.

An expert survey is being carried out, and all of the industrial building’s rare architectural and technical elements are being carefully described, catalogued, and expertly removed in such a way that will ensure they can subsequently be returned. This includes the overhead crane, which we have decided to completely restore and to return to the new Kunsthalle as an historical artifact. Its story reflects daily life in the technological heart of the former converter station as well as the station’s architectural history. 

When it began operating in 1932, the Prague Electricity Works’ first ever converter station measured 1,934 sq. metres. The intricate reinforced concrete building was divided into four main parts: a residential area, a machine room, the transformer station (converter station), and the switching station. The mentioned crane was anchored on a frame construction in the machine room, where its hook and strong chain were used to unload transformers and other equipment from trucks. However, because it moved along a track that extended beyond the beveling of the hall’s walls, the architect Vilém Kvasnička had to design a solution in the form of external columns supporting the building’s corner. The addition of an exterior arcade not only met the technical requirements for the crane’s operations, but also elegantly matched the stylistic character of Lesser Town architecture.

Hidden Danger in the Concrete

Over the course of several years, the architectural survey of the original Zenger Transformer Station revealed numerous fascinating historical details as well as many complicated obstacles.* 

The high demands in terms of temperature, humidity, load-bearing capacity, and fire safety (in the areas where art will be displayed), led us to decide that we had to insert a new monolithic wall structure into the original perimeter walls and to add insulation. What is more, in order to be able to preserve the perimetry masonry at all and to add an extra underground level, we had to anchor these walls to temporary steel structures, thus constructing braced sheeting inside the building. This was a truly hard nut to crack. The exterior steel supports could be erected only on the southern side of the building and the other walls had to be supported using interior steel supports – at the same time, these supports had to make it possible to pour the concrete for the reinforced concrete constructions inside the building.

We also discovered that the interior load-bearing constructions were constructed using high-alumina concrete, a special type of material whose main ingredient is calcium aluminate cement. When the station was built in the 1930s, this was an innovative new technology, with a rapid setting time that significantly accelerated construction. Over the years, however, experts came to realize that this type of concrete very quickly loses its original rigidity and significantly interferes with the critical reinforcing steel rods. In fact, high-alumina concrete was behind several tragic building collapses in Czechoslovak history, such as the accident at the state-owned MESIT factory in Uherské Hradiště in 1984. It also resulted in the premature demolition of the Baťa Palace in Mariánské Lázně and the closing of part of Brno’s Faculty of Law building in 2018. 

Today, high alumina concrete is banned from use in load-bearing structures, and so we were forced to remove all structural elements containing this type of concrete from the former Zenger Transformer Station. The interior structural integrity had been irreversibly damaged and the risk of collapse was too great. The building’s poor technical state was further worsened by substantial chemical contamination from the petroleum oils and mercury that were necessary for the operation of the transformers. All polluted materials are being removed to a special dump for toxic materials.

“All damaged structural elements absolutely had to be removed. The extent of the demolition work resulted from the building’s structural and technical state, which was further worsened by its contamination by mineral oil and mercury. The north-eastern facade, where this state of affairs had the greatest impact, will be returned to its original appearance, including the proper profiling. The interior, however, will be adapted for its function as a gallery space. The original divided interior will be replaced by a looser and more open layout allowing for greater variability in the planned exhibitions,”

explains architect Zuzana Drahotová of Schindler Seko. 

However, this does not mean that these necessary interventions have robbed the building of its original purpose. Thanks to the converter station’s modernisation, all of the technical equipment necessary for converting alternating current into direct current is located in the building’s basement and continues to feed Prague’s trams. The upper floors of the Kunsthalle, meanwhile, will be reserved for people and art.


*
Once the structural elements of the original transformer station had been removed, it become necessary to make use of ground-penetrating radar, which allowed us to scan and create a profile of the subsurface. This process led to several important discoveries. It showed that the ground under the northern part of the building consists of a protrusion of bedrock, while underneath the southern part are alluvium deposits from the Brusnice Creek and the lost cellars of the former Bruska Barracks. 

The Secrets of the Raumplan

Architect Vilém Kvasnička’s original Zenger Transformer Station is sometimes called a building with two contrasting extremes. What are they? And what is left of them in the future Kunsthalle Praha? 

In designing the building’s formal morphology, Kvasnička decided to sensitively respond to the context of the place and the period of construction, meaning the existing historical architecture of Prague’s Lesser Town in the early 1930s. However, behind the station’s charming neoclassical facade, he was not afraid to engage in daring modern architectural experimentation based on the use of a Functionalist reinforced-concrete structure of an industrial nature. It is specifically this approach that has been preserved in the architectural identity of Kunsthalle Praha as designed by Prague’s Schindler Seko architect studio. 

“Our main goal was to simply open up the building to people, to let them into places where everything had been dead and closed, locked up and empty. To let the building breathe again. The building was full of technical equipment and transformers. In contrast with its neoclassical facade, the interior was very industrial, cut off from the public, and did not match the windows. The concrete interior had to be replaced, and we replaced it with a similar concrete structure, except that the interior levels now communicate with the facade and the world outside. I think that Kvasnička, the building’s original architect, would like this idea,”

speculates architect Jan Schindler, co-founder of Schindler Seko Architects. 

The new monolithic structure is inextricably linked with the original elegant façade, and together they form a unique space for the future art gallery. The façade has retained its modestly decorative Neo-Classicist style, except that it has been expertly cleaned and restored. The windows and large gates have been given their original light grey hue. The only change is that the former opaque wire glass has been replaced with clear, transparent glass. What was originally a technical building has regained its former greyish-beige colour. The building has also finally been given a highly visible main entrance (in the past, it was no more than an inconspicuous technical door) in the form of a gleaming footbridge leading to the entrance door – specifically it is an elegant triangular pyramid shape made of bronze-coated stainless steel (imitation bronze construction) and is completely tiled in a characteristic Prague mosaic pattern. 

“The facade reflects a Raumplan layout [“spatial plan” – author’s note], and the spaces beyond it should logically correspond to it. And the Raumplan concept is perfectly suited for a gallery space. It has offset levels and long lines of sight for people, with energy of movement up and down. The space is constantly changing. Since it is a publicly accessible building, we have designed a ramp with a new entrance to the building that leads visitors into a raised entry hall. In this way, visitors have a magnificent view when they enter this beautiful space. This has been a defining element along with our use of a Raumplan concept since the very beginning, just like the third level of the gallery space, which we added above a part of the roof,”

says Jan Schindler in revealing that a key source of inspiration was the famous Austrian architect Adolf Loos. 

In his buildings and designs from the early 20th century, Loos, a leading representative of architectural purism was already promoting the concept of the Raumplan – a spatial plan that broke down the traditional horizontal links between building storeys. According to Loos, his approach to architecture had “no ground floor, upper floor, etc., only contiguous, continual spaces.” 


The moment you begin your exploration of the interior of Kunsthalle Praha, you will experience the same moment of surprise that the architect Kvasnička incorporated in his design back in 1930. The first thing you see is the appealing historicist facade, but when you enter the building you suddenly find yourself in an industrially rational and suitably grand space with fluidly connected storeys, the construction of which is dominated by concrete, for instance the type of concrete called “bush-hammered”.** As stated in an article by the designers that was published in the STAVBA architectural magazine, “A logical distribution of the spaces at various heights arises in the central and southern parts of the building, which is a precise continuation of the window openings in the original Neo-Classicist façade.” 


**
The colour of such concrete depends on the type of stone used in its production – in this case basalt, a natural stone with a lifetime spanning centuries, if not millennia. In order to avoid adding any other stones that would result in an unwanted change of colour, the concrete plant had to set up a special stone warehouse exclusively for Kunsthalle Praha.

Let There Be Light!

The original technological terrace of the Zenger Transformer Station, which, in today’s Kunsthalle is dominated by a new single-storey extension with a brushed terrazzo surface (a cast floor containing pieces of historic copper cables), is in itself interesting evidence of the search to identify the modern, yet also historical, identity of Prague in the 1930s. In the past, this whole space made no sense from the perspective of the station’s operations, but it played a key role as it functioned as something of a false wall with the aim of completing the mass of the building and reliably obscure the view of the flat, strictly technical roof.

In his day, the architect Vilém Kvasnička executed a perfect act of camouflage – for the interior, he designed a modern oasis for the technology required to produce electricity, but for the exterior, he preserved the image of a metropolitan palace that paid respect to the rich history of “its” city. Although at that time the terrace with an ornamental railing (balustrade) may have only been a part of an ingenious covering game, now, in the presence of Kunsthalle Praha, it has achieved true meaning for the first time in its history – it has become an inseparable part of the cafe, a place bathed by the sun’s rays, rain and snow, where, with coffee in hand, you can enjoy a unique view of the Klárov quarter, Prague Castle, and Petřín Hill.

The daylight enters not only the café but also the entire third floor where Gallery III is situated through an enormous window connected to the Zenger Promenade – now the Kunsthalle’s second vista point, this time overlooking the greenery, the beehives beneath the Kramář Villa or the neighbouring charming structure from 1909, and the building that originally housed Adolf Klar’s Institute for the Blind and later became the House of Body Culture and the site of Prague’s first steam bathhouse. Incidentally, another significantly fascinating source of daylight in Kunsthalle Praha is the atypically elongated skylight at the western ridge of the roof, which is one of the most popular places for photographers specifically because of its dizzying verticality.

Ten Letters That Embrace Kunsthalle

Our building is now unmissable. In addition to the metallised  entrance footbridge, the bronze Kunsthalle signage now gleams brightly on its corner – not unlike the proud display of a ship’s name on its bow. You can see it from different angles while riding the tram (lines 2,12,18, and 20) or when strolling through Prague’s Klárov.

The concept for the typographic sign on the building’s corner came about five years ago when Studio Najbrt was developing the logotype. The unusual solution is a natural result of the structure’s specific morphology and history – the Kunst font itself, designed by graphic designer Marek Pistora, is based on a sketch by German typographer Jan Tschichold from 1930, the same time when construction work on the Zenger substation began. 

“Mounting the letters on the façade required numerous adjustments and testing, paper and 3D models, and visualisations, including the necessary reinforcement of the central strokes of the Kunst font. The resulting metal signage is by far our largest typographical execution in public space,”

says graphic designer Zuzana Lednická of Studio Najbrt about the sign, a friendly mashup of the historical and the contemporary. 

For the Detail Lovers:

All ten letters are made of closed stainless steel sheet metal boxes coated in bronze (the same process used on the new entrance footbridge in the form of a  triangular pyramid), and then anchored to the building’s neoclassical façade on secure stainless steel spikes. 

Starring:

on behalf of Studio Najbrt – Marek Pistora (typeface), Andrea Vacovská (visual style), Zdeněk Trinkewitz (3D & paper models), Aleš Najbrt, Zuzana Lednická (art direction). 

Overview of Kunsthalle Praha

7 storeys

(2 belowground and 5 aboveground)

6–8 exhibitions

a year

3 galleries and exhibition spaces

2 terraces

1 bistro

1 café 

1 collection

(but not permanently exhibited – each year we will organise a programme of short-term exhibitions, which may, but do not necessarily have to, include works from the Kunsthalle’s collection)

Interesting Numbers

A total of 2,300 individuals participated in the conversion, and there were 252 suppliers. There are 230 kilometres of cables winding through the building, and its monolithic frame, concealed behind the Neo-Classicist façade, contains 12,690 tonnes of concrete. The lifts installed at Kunsthalle accommodate large artworks, and even a car. The foundation joint of the building is situated 30 centimetres below the surface of the Vltava River, and a crane measuring 55 meters in height was used at the beginning of the construction.

Technical Information

Building location:

Usable area:

Klárov, Praha 1

5687 m2

Architects:

Project Architect:

Jan Schindler, Ludvík Seko,
Zuzana Drahotová / Schindler Seko Architects

Zbyněk Ransdorf, Jana Šerclová / AED project

Investor:

Plot area:

Nadace The Pudil Family Foundation

2287 m2

Cooperation:

Design phase:

Martina Bílková

2014–2021

Built-up area:

Implementation:

cca 1650 m2

2018–2021