This research addresses the enhancement of outdoor Cultural Heritage by exploring innovative methods for integrating different digital models applied to external environments, with a specific focus on so-called ‘Vegetal Architectures’. These spaces, shaped by the interaction of natural and built elements, embody historical processes of continuous transformation and therefore require survey methodologies capable of combining material data with the reconstruction of the site’s evolutionary history. Among the case studies examined, the Pincio Promenade in Rome plays a central role. Designed by Giuseppe Valadier from 1810, it represents one of the most significant nineteenth-century urban interventions in the city. Despite its cultural relevance, existing graphic documentation remains fragmented and inadequate for an accurate architectural-scale description of its metric and geometric features. A key historical reference is the Plastico di Roma da Piazza del Popolo a Piazza Colonna con il Pincio, a maquette made by Tommaso Falcetti under Valadier’s supervision from 1822, which provides a valuable topographical record of the area. The study aims to produce a detailed digital survey of the Pincio Promenade through the integration of Terrestrial Laser Scanner (TLS) and Simulta- neous Localization and Mapping (SLAM) technologies, generating numerical discontinuous and continuous models suitable for the analysis of Vegetal Architectures. In parallel, a high-resolution digital reconstruction of the Plastico di Roma is developed using colour-calibrated Structure from Motion (SfM) photogrammetry and hybrid laser scanning. The resulting models are then compared to validate the contemporary survey and to investigate the historical transformations of the garden.

Building Information Modelling (BIM) and Life Cycle Assessment (LCA) are increasingly integrated to support environmental assessment in the built environment. However, applications to existing and heritage buildings remain fragmented, and the contribution of Heritage Building Information Modelling (HBIM) to Life Cycle Assessment is still poorly defined. This study presents a systematic review of 41 peer-reviewed publications retrieved from Scopus and reported according to the PRISMA 2020 guidelines, combining bibliometric, thematic and workflow-oriented analyses. Studies were selected according to predefined eligibility criteria based on relevance to HBIM-LCA integration. Three main BIM–LCA workflow typologies are identified: manual/export-based, plug-in-based and IFC-enabled interoperability approaches. While these workflows have progressively improved automation and data exchange, their application to existing and heritage buildings remains largely scenario-driven and focused on comparing refurbishment, retrofit, adaptive reuse and reconstruction alternatives. The review shows that HBIM distinctive contribution does not lie in environmental calculation methods, but in its ability to structure knowledge related to existing assets, including conservation state, intervention history, information provenance, uncertainty and life cycle transformations. However, current HBIM information structures remain only partially aligned with LCA requirements, particularly regarding service life, end-of-life scenarios and knowledge management. Semantic technologies emerge as a promising pathway towards knowledge-level interoperability. Limitations are related to the heterogeneity of the reviewed studies and the predominance of qualitative evidence. Digital-Green Heritage Workflows integrating HBIM, LCA and semantic technologies enable more transparent, life cycle-oriented and sustainable heritage conservation.