Extensive green roof terrace as a restoration solution at Bethlen Castle in Bahnea

3 min read

The restoration of Bethlen Castle in Bahnea is one of those projects that forces you to slow down and rethink every step ten times before taking it. This is not a new construction, where rules are clear and materials “behave,” but a historic building layered with history, old mistakes, and a significant amount of moisture accumulated over time.

A distinctive aspect of the project was the integration of underground structures into an extensive green roof terrace, a solution that not only protects the hidden structures but also actively contributes to the hygrothermal balance of the entire complex.

Under the general contracting of Multinvest Group from Târgu Mureș, the intervention began with a harsh reality: water had penetrated everywhere it shouldn’t have—into the walls, vaults, roof structure, and façade details. The restoration process was conceived as a logical sequence, not as a show of force. First came the strictly necessary emergency interventions to stop accelerated degradation. These were followed by functional rehabilitation, then the conservation of valuable elements, and finally the restoration itself, carried out with respect for materials and techniques compatible with the historical period.

This green terrace is not a simple “modern add-on,” but a natural extension of ecological construction and responsible restoration. It supports drainage, reduces temperature fluctuations, limits condensation, and brings nature back to a place from which years of misguided interventions had pushed it away.

Today, Bethlen Castle is not merely “repaired,” but re-taught how to function properly, in harmony with its environment and with its own history.