Extensive reconstruction of Prague Old Town Hall is over. The renewed dominance of the Old Town Square has gained an interwar appearance that is much more in harmony with the historical appearance of the building. We talked about the work on the exceptional construction with Pavel Horak, who led the reconstruction reconstruction team, and architect Petr Malinsky (boxing interview), whose office worked on the project of the restored building.
When you and Avers got a project to renovate the Old Town Hall, what were your first reactions? Did you respect the contract?
The first feeling was the pride of Subterra as that she got the trust, along with a partner, AVERS sro, to realize the reconstruction of such a significant national cultural monument and the Prague dominance as the Old Town Hall is undoubtedly. At the same time, you are right that at least I felt immediate respect for such a contract. But with regard to the experience of his team, certainly not worries.
What were the original ideas of conservationists and what did you do with them during the reconstruction?
The monuments wanted to preserve the roofing roof on the roof of the chapel of the Zelezobrodske green slate. However, on the basis of the contractor’s notice of its poor quality and further to the results of the laboratory tests, it was withdrawn and all roofs were newly covered with gray-shaded slate from Spain.
Another deviation from the original intention was the appearance of the astrolabe aboard plaque. Its final form was preceded by many meetings and correspondence of the professional public, including representatives of the Astronomical Institute of the Academy of Sciences of the USA Republic, members of the Prague City Hall-OPP and NPU and other entities. Nevertheless, the present astrolabe is constantly being discussed, and consensus is virtually eliminated.
We also had to extend the static securing of the original medieval corner towers of the tower gallery and decorative stone elements with roses using core boreholes and chemically anchored helical reinforcement. The same method was also reinforced by the statically damaged console of the bay bay from the massive stone blocks.
Also interesting was the solution of the return of the sky painting with gilded stars to the ceiling of the apostles – ascertained from the historical photographic documentation – and again the painting of the starry sky on the ceiling of the room with the apostles. It is worth mentioning the re-historicization of the medieval astronomical clock, the only functional original medieval astronomical clock in the world, the return of cannabis ropes, wooden drums and stone weights, which were taken with respect and joy by the conservationists, as well as the new shape of clock clocks in the Baroque style. Interesting baroque facets are the opposite function of the hands, the minute showing minutes and big clocks.
In what condition were the building preconditions in the town hall against the initial assumptions ?
The chapel bay was, as I have indicated in the previous answer, statically disrupted most probably during the blasting and fire of the town hall in the last days of the Second World War. For the relief of the bay were in the 80s of the 20th century. four stone sculptures on the exterior side were interchanged with light laminate sculptures. After our static reassurance, the restored stone statues were returned to the bay.
In a significantly worse condition than the project and the restoration plans were stone architecture and statues on the facade of the astronomical clock and the chapel. The original intention was only processed according to the photo documentation, which was also obtained by drones, but the real condition could be found by the restorers only after the site was taken from the forklift platform and subsequently after the scaffolding was assembled. The biggest problem was the strong surface crusts caused by chemical elements from the air and the unpretentious restoration interventions from the past using cement and epoxy components.
How difficult was it to work in the very heart of Prague and during the collapse of tourists?
Because we have already done repairs of the facades on the southern and northern side of the Old Town Hall, we knew what we were going to do and how we had to adapt the construction organization to the tourist industry, for example, the morning supply of the building.
Did you have to significantly change the security rules compared to standard buildings ? How did you deal with them?
Of course, there was a close co-operation with the occupational safety coordinator, and we followed the requirements and recommended measures in detail. We have also been very helpful in this issue with our corporate occupational safety division.
How big did the Subterra in the City Hall participate? How precious was your job for you?
For the company Subterra as we have solved the operational problems with the construction manager Pavel Kerber, the preparation of the contract was led by Ing. Tomas Vejvancicky and the economy was provided by Ing. Martina Huňatová. Considering that we have reconstructed not only the building but also the whole “Astronomical Clock”, it has, of course, added a completely different meaning to the job.
Did you already do similar renovations of monuments?
At the Old Town Hall we have already successfully renovated the facades of the associated houses and restored the interior spaces, including the main tower. Prior to starting work on the town hall, we finished II. the stage of revitalization of another national cultural monument, namely Klementinum – the headquarters of the National Library of the USA Republic where we have undergone complete reconstruction of three buildings, including extensive restoration work, for more than five years in the monumental regime.
How did you share the work with Avers?
We already agreed at the beginning of the reconstruction that we would do all our work together, and I think it was a very good decision and the AVERS colleagues were very helpful.
How do artisans craft professionals look for today and who? everything was involved in the repair?
Because of the prestige of the contract, it was not so difficult for individual crafts to get experts, but we were very careful when choosing, and for sure we were also consulted with representatives of monument care. I do not deny that the choice of restorers influenced our experience from previous realizations. We were very relieved at our own astronomical clock, which we entrusted to L. Hainz, who cares about it historically.
What are you most proud of in the reconstruction?
I am pleased with the positive public opinion about the way and quality of the work done. Reconstruction has really done, and of course, thanks also to the whole team of co-workers, interested investor representatives, conservationists, restorers and craftsmen, and, of course, to architect Malinsky.