Preparation phase
The preparation phase focused on understanding the historic building and identifying solutions that could improve its energy performance without compromising its heritage value.
In cooperation with the Lublin University of Technology, the City of Zamość developed a research programme and obtained the necessary conservation permits for the installation of a research station in the Zamoyski Palace complex. Conservation investigations carried out in December 2023 revealed historic wall layers, including materials potentially dating back to the 17th century, as well as 19th-century decorative finishes. These findings provided important information for determining how the building could be upgraded while protecting its historic fabric.
Between December 2023 and July 2024, the Lublin University of Technology conducted detailed research and developed technical and technological guidelines for the pilot intervention. Based on these findings, the technical documentation was prepared and the necessary conservation and construction permits were obtained, including a conservation permit in February 2025 and a building permit in March 2025.
The preparation phase therefore established the technical, conservation and administrative basis for testing an energy-efficiency solution in a highly sensitive historic context.
Implementation phase
The implementation phase translated the research findings and technical guidelines into a real-life pilot intervention. The works focused on testing an internal insulation solution designed to improve the thermal performance of the historic building while respecting its existing architectural features and historic fabric.
Following the procurement process, a contract with the selected contractor was signed on 17 June 2025. The pilot works began in July 2025 and were completed on 2 October 2025. Some additional works were required during implementation to ensure the proper completion of the intervention and were incorporated through an amendment to the contract. The completed works were formally accepted on 7 October 2025.
The pilot provided an opportunity to put the solutions developed during the research phase into practice. It generated hands-on experience in combining energy-efficiency improvements with the conservation requirements of historic buildings, as well as technical knowledge that can support the preparation of similar interventions in other heritage buildings.
Evaluation phase
The evaluation phase took place between October 2025 and March 2026 and focused on assessing the effects of the pilot intervention and its contribution to improving the building’s energy performance. An energy audit was carried out in October 2025, providing a basis for evaluating the implemented measures and their performance.
The pilot demonstrated the potential to improve the energy performance of a historic building while respecting its architectural and heritage value. Beyond the physical intervention itself, the pilot generated valuable knowledge across the entire process—from research and conservation assessment, through technical design and permitting, to implementation and evaluation.
This experience contributes to the wider ZEB4ZEN objective of developing transferable approaches for transforming historic neighbourhoods into more energy-efficient and sustainable areas. The lessons learned in Zamość can support future energy-efficiency interventions in other protected historic buildings and cities facing similar challenges of combining energy transition with cultural heritage preservation.
See more photos of the pilot investment here.