Abstract

Introduction Climate change is modifying the climatic assumptions embedded in building regulation, urban regeneration policy and real estate valuation. In Spain, building-code climate zones combine winter and summer climatic severity, which are directly linked to heating demand, cooling demand, thermal comfort and envelope-performance requirements.Methods This study develops a GIS-based scenario assessment of projected climatezone shifts in Spain under RCP4.5 and RCP8.5. The empirical database integrates 7,966 valid municipal observations and 77 AEMET/AdapteCCa climate-station observations, including recalculated present classifications and projected classes for 2055 and 2085. The analysis measures municipal class change, winterseverity shifts, summer-severity shifts, A4/B4 high-summer-severity concentration and valuation-materiality channels for ESG-oriented urban regeneration.Results Results show a substantial reconfiguration of Spain's building-climate geography. Relative to the recalculated present classification, 84.2% of municipalities change class under RCP4.5-2055, 85.0% under RCP4.5-2085, 93.2% under RCP8.5-2055 and 93.2% under RCP8.5-2085. Under RCP8.5-2085, 88.9% of municipalities move toward lower winter severity, while 66.1% move toward higher summer severity. The dominant future classes become B4 and A4, representing 41.7% and 39.8% of valid observations, respectively.Discussion These findings indicate that chronic warming may reduce winter severity while intensifying summer stress, shifting building-performance priorities from heating-dominated assumptions toward cooling resilience, overheating prevention and adaptation-oriented retrofitting. The study provides a reproducible pathway for linking climatezone transition intensity with building vulnerability, socioeconomic sensitivity, ESG regeneration priorities and real estate valuation materiality.