Retrofitting for resilience and climate-oriented transformation of existing buildings through green and blue infrastructure elements

Abstract

such as green roofs, façades, rainwater harvesting, and permeable surfaces can be integrated into the retrofitting of existing buildings to support climate adaptation and urban resilience. While retrofitting is increasingly recognized as essential for sustainability, current practice remains focused mainly on energy efficiency, often neglecting ecological and spatial dimensions. The research combines a targeted literature review with eight professional questionnaires and several semi-structured interviews involving architects, planners, municipal officials, researchers, and sustainability consultants. This qualitative approach helped identify both conceptual and practical gaps in how GBI elements are planned, financed, and maintained in building retrofit projects. Findings reveal that although awareness of GBI benefits, such as improved thermal comfort, flood risk reduction, and biodiversity enhancement is growing, implementation remains limited. Key barriers include rigid regulations, fragmented governance, financial constraints, and a lack of cross-disciplinary collaboration. Stakeholders perceive these challenges differently: designers and planners highlight environmental and spatial quality gains, investors focus on economic return, and municipalities balance enabling policies with administrative restrictions.

The study concludes that meaningful GBI integration depends on early-stage planning, stronger cooperation across disciplines, and policy frameworks that value existing buildings as long-term environmental assets rather than short-term liabilities. By connecting academic knowledge with real-world professional insight, this research proposes guidelines and an adaptable framework to support the practical inclusion of GBI elements in retrofitting processes. Ultimately, it argues that integrating green and blue systems is not only a design improvement but a crucial step toward resilient, climate-adaptive urban transformation.