Energy-Efficient Restoration of Historic Buildings: Mapping Decarbonization, Conservation-Compatible Retrofit Strategies, and Sustainable Tourism with Implications for Stone Places of Worship

Historic buildings occupy a sensitive position in contemporary energy and heritage management because they combine building-performance requirements, material-conservation constraints, and dynamic patterns of use. This study maps the broader historic-building literature at the intersection of energy-efficient restoration, building decarbonization, heritage conservation, and sustainable tourism, and interprets the resulting bibliometric structure with particular implications for historic stone places of worship. Records were retrieved from the Web of Science Core Collection and screened through a PRISMA 2020-aligned protocol, yielding 804 publications. Accordingly, the 804-record corpus represents a broad historic-building and heritage-management evidence base rather than an exhaustive dataset restricted exclusively to stone religious buildings. Performance analysis and science mapping were conducted using Bibliometrix, while bibliographic coupling and longitudinal thematic-evolution analyses were added to examine contemporary research fronts and their temporal continuity. Co-citation analysis identified two partially separated intellectual schools—European conservation microclimate and adaptive reuse management—whereas bibliographic coupling revealed five current research-front communities, including adaptive reuse and sustainability, microclimate-conservation-energy, and an emerging HBIM/digital-documentation front. Thematic evolution showed increasing post-2019 convergence of tourism and management with conservation and cultural-heritage research, but continued separation from technical energy and microclimate streams. The study therefore moves beyond descriptive rankings to identify structural fragmentation and three priority directions: integrated monitoring of visitor loads, energy, and conservation performance; HBIM-supported spatial integration; and stronger cross-national research collaboration. The findings are interpreted as bibliometric evidence and research-agenda signals rather than as causal proof of building or policy performance.