## 2 Comparative Review of Life Cycle Analysis Tools for Building Assessment  
### Existing LCA/LCC Tools and Methods  
The field of building assessment has produced various LCA tools that evaluate the environmental and economic impacts of construction and renovation projects. While these tools have significantly advanced sustainability practices, they exhibit certain limitations, particularly when applied to dynamic scenarios such as building renovations under atypical conditions. This section provides a comparative overview of widely used LCA tools, identifying their strengths and shortcomings to set the stage for how VERIFY addresses these gaps in the next subsection.  
Several established tools are frequently used for LCA and LCC in building assessments, each focusing on specific aspects of sustainability and performance. SimaPro, for instance, is a versatile tool applied across various industries, including construction, offering robust data modeling and environmental impact assessment capabilities [36]. However, its broad applicability often requires extensive customization for construction-specific applications and lacks modules tailored to operational energy performance or renovation scenarios. Similarly, the Athena Impact Estimator for Buildings, designed for the North American construction sector, facilitates detailed assessments of embodied energy and emissions through its comprehensive material database [37]. Despite its strengths in material impact analysis, Athena's limited capability for operational energy modeling and lifecycle economic evaluations restricts its scope for comprehensive building performance analyses. RESTcreen, on the other hand, is widely used for renewable energy feasibility studies and performance analysis, offering an integrated platform to evaluate energy efficiency measures, cost savings, and emission reductions. While RETScreen excels in energy performance and financial analysis, it is less suited for detailed lifecycle environmental assessments [38].  
In Europe, One Click LCA software is widely used for its integration with Building Information Models (BIM), streamlining LCA processes for architects and construction managers [39]. Its alignment with European standards and extensive material database makes it particularly effective for material impact evaluations. However, as of v1.0.4.0, its primary focus on material impacts limits its flexibility in addressing scenario-based analyses or dynamic simulations, which are essential for assessing renovation strategies. Tally, another tool integrated with BIM, excels in evaluating embodied carbon and resource use during early design stages [40]. While valuable for preliminary assessments, Tally's limited applicability to post-construction evaluations and operational energy modeling reduces its suitability for comprehensive lifecycle analyses of building renovations.  
Despite their contributions, existing tools often face limitations when applied to dynamic building renovations. Most are designed for static evaluations, which restricts their ability to simulate changing operational conditions, such as occupancy shifts or evolving energy demands. For example, many tools emphasize material-focused analyses or short-term performance, making them less effective for evaluating long-term impacts or responding to disruptions like the COVID-19 pandemic. Additionally, limited scenario flexibility and a lack of advanced simulation capabilities hinder the comprehensive assessment of lifecycle costs, payback periods, and renovation strategies. Tools optimized for specific regional markets further reduce their adaptability to global or multi-regional contexts.