A Sustainable Approach to Reconstruction: Historical Roof Structure Interventions

The reconstruction of structural subassemblies in historic buildings is a widely debated topic that often arises throughout a building’s lifespan. The most vulnerable structures and, consequently, the most frequently modified are roofs, due to the materials used, which render them susceptible to biological decay or fire. This paper aims to analyse roof reconstructions across various historical periods and under different circumstances depending on the necessity for construction or reconstruction. Several exceptional reconstructions from Europe are examined, where the final solution was determined based on sustainability criteria from the construction period. Wood in roof trusses is often replaced with alternative materials such as metal or reinforced concrete. In the case of the Evangelical Church in Bistrița, destroyed by fire for the second time in 2008, the solution of replication using wood was adopted, and the wooden elements were calculated for fire resistance, according to the Eurocodes. Another important aspect to consider when constructing new roofs is the need for protective or temporary roof structures, where sustainability and reusability are fundamental requirements. The principles used to choose the covering method were different depending on the reconstruction period. Three analysis criteria were defined to compare historical solutions with current sustainability principles in the reconstruction and construction of new roofs for existing buildings.