A partly retractable roof covering the ruins of the Church of St John the Baptist at Žička Kartuzija, the oldest charterhouse in Slovenia, has won the architects the top national prize in architecture on top of international accolades.

Rok Žnidaršič, Jerneja Fischer Knap, Samo Mlakar, Katja Ivić and Dino Mujić of the architectural studio Medprostor received the Plečnik Prize at a ceremony in Ljubljana on 20 May, having already collected the 2022 Piranesi Award, and the third place in the theme category at the 2023 Balkan Architectural Biennial for the project.

The judging panel praised their innovative approach to the fragile cultural heritage.

The 12th century Carthusian monastery near the northeastern town of Slovenske Konjice has been in ruins for almost 200 years, having been dissolved by emperor Joseph II in 1782.

Conservation experts believed that such important ruins needed a roof, but there was a dilemma whether it should resemble the original Gothic phase of the structure for which there were no written records, or whether to preserve the monumental effect of the church open to the skies.

Medprostor successfully combined the extreme and seemingly incompatible conservative and modern ideas to produce "a modern, open and abstract architectural language", the Plečnik Prize judges said.

Their roof protects the ruins against the elements but also reinterprets them. It can accommodate 12 visitors and a tour guide at a time, which corresponds to the number of monks and prior who lived at the monastery.

The €3 million renovation of the church's walls along with the roof, an access corridor, two staircases for visitors and an observation point started in 2020.

When inaugurated in 2022, the roof raised eyebrows among some architects and art historians.

The Plečnik Prize has been presented annually since 1973 by the Jože Plečnik Fund, named after Slovenia's greatest architect Jože Plečnik (1872-1957).

Along with Plečnik Medals, it was handed out at a ceremony at Plečnik House. The winning projects are on display at the Dessa Gallery in Ljubljana.