An ambitious idea: glass gable roof for the Pirita monastery

Pirita monastery. Photo: Mihkel Maripuu

• The technology of building glass facades has made raid progress in recent years.
• Frameless glass panels can cover large surfaces.
• A flat roof is inappropriate for a sacral building.

The architect Andrus Kõresaar and conductor Tõnu Kaljuste, the arts director of the Birgitta Festival, last week presented at the Pirita district council the idea of building a roof over the ruins of the Pirita monastery.

It has been discussed repeatedly over the years and the Pirita district administration has by now decided to allocate money from the city’s supplementary budget for a study of the monastery walls. The new aspect is the architect’s and the conductor’s vision of a gable roof made of glass.

Pirita district administration head Tõnis Liinat (KE) has presented to various national heritage protection boards the plan of a flat and possibly foldable roof, hidden behind the walls. The Heritage Protection Board also recommended which firms would be suitable for carrying out the studies and the best bid from among them was selected.

“The ruins of the monastery have an established, iconic shape. Whichever way you look at them, there are the high gable and lower walls. The solution could involve building a gable roof of the same shape as historically, but as transparent as possible, with a minimal metal support structure,” Kõresaar told the district council.

Rapid development continues

He explained that the technological solutions for glass facades have made significant progress in recent years and that rapid development continues even now. At the same time, all the consequences of building a glass roof must be taken into account.

“The sun definitely shines through the glass, even if you use glass material with high UV protection factor. Another thing that accompanies any glass surface is the acoustic concern. So if you organize classical music concerts there, an internal acoustic solution is needed,” the architects aid.

Since, according to him, classical music concerts would probably also need twilight, there could be a cover moving on rails. “Something like this has been done, for example, in the Noblessner foundry, which has a historic glass roof. During concerts, a blackout curtain is pulled in front of it, which obscures the light and acts as an acoustic damping device," Kõresaar said.

According to Liinat, he has consent for planning a flat roof. “The heritage protection requirement was that there would definitely be no gable roof. The roof could have a maximum angle of 10-15 degrees to allow rainwater to run off.”

Kaljuste said that all the talk about a flat roof is a big surprise for him. “To my knowledge, no church in the world is being restored with a flat roof. A flat roof would be unique for a sanctuary and indeed very ... flat,” he thought.

Cautious optimism

Kõresaar and Kaljuste have also presented their ideas to the city government, where they have been received with cautious optimism. Deputy Mayor Kaarel Oja (SDE) stated that the issue of building a roof over the Pirita monastery is raised every few years. “I think that the reason of this return to the issue is that the annual setting up of an opera tent in the context of the Birgitta Festival is expensive and expends a large part of the money that could be spent on the festival program,” Oja said.

He added that this debate can only be very calm, thoughtful and unhurried. “But I am very much in favor of us being able to approach this issue calmly, step by step. As for the studies, even if the results rule out any roof-building plans, we shall have a clear idea of the state of the monastery walls and what needs to be done to preserve them,” Oja says.

Deputy Mayor Madle Lippus (SDE), who is in charge of Tallinn's heritage protection, added that this subject should be discussed within this sphere first of all, because this plan would conceptually change the essence of the monastery ruins as a monument. “In case of a monument, it is always very important to consider its usability. On the one hand these are ruins and that is very important. But it would also be very good if the ruins of the monastery had some function or an additional meaning,” Lippus said.

The former owner of the monastery ruins, the Order of Birgitines currently operating in their neighborhood, has not yet formed its position. Ott Rätsep, who is one of the representatives of the Order in the co-operation assembly of the monastery ruins park, said that he personally does not consider the idea of a roof a mortal sin. “But the order cannot form its position until they have seen what is really going to be done there. And maybe the position will be formed not here, on the spot, but in Rome,” Rätsep said.