Alternative Construction Pathways for Climate Adaptation - Evaluating Demolition, Reuse, and Renovation Strategies

Abstract

The construction sector is under increasing pressure to address the challenges of material durability and climate change adaptation. Recent European policy developments, especially the revised Energy Efficiency Directive (EED) 2023/1791 require a systematic comparison assessment of demolition versus renovation for public buildings to balance lifecycle carbon emissions with improved energy performance. This study investigates the potential to reduce embodied carbon by evaluating three strategies: (I) demolition with new materials, (II) demolition with material reuse and recycling and (III) renovation and extension. The assessment framework uses the European EN 15978 standard and the European Commission’s Level(s) method, contextualised to Estonian conditions over a 50-year reference period. Three building archetypes - a daycare centre, an office building and a rescue command complex, were analysed to represent diverse historical contexts and structural conditions. Results indicate that renovation (Scenario III) is the most carbon-efficient strategy when building functionality remains consistent, as seen in the office building which achieved a 40% lower fossil carbon footprint compared to new construction (Scenarios I and II). Conversely, for the rescue command complex, which required significant structural reconfiguration to meet upgraded demands, new construction with reused materials (Scenario II) proved more climate-efficient than renovation (scenario III). Across all scenarios, the product stage (A1–A3) was the dominant source of embodied carbon emissions. The findings suggest that while renovation is often preferable, the optimal environmental pathway depends heavily on the scale of functional transformation and the potential for material circularity.