## 1 Introduction
### Gaps and Research Objectives  
The right to independent living has been widely recognized as a fundamental principle for people with disabilities, as established by the Convention on the Rights of Persons with Disabilities [9; 24; 36]. This right entails not only the freedom to choose where and with whom to live, but also the need for environments that support autonomy and full participation in everyday life [25; 37]. In this context, housing plays a central role as a space for personal and social development [26; 27; 38]. Despite these advancements, explicit gaps remain evident in the current literature and practices, highlighting significant limitations that require further research attention. Specifically, three primary gaps have been identified, which are outlined below:  
* Lack of standardized and user-centric methodologies: Existing approaches predominantly address minimum regulatory requirements without sufficiently integrating user experience and real-life functional needs, resulting in solutions that frequently fall short in practical contexts.
* Limited customization in accessibility assessments: Current regulatory frameworks typically adopt generalized criteria, inadequately accounting for the diversity of individual capabilities, preferences, and daily challenges faced by people with disabilities. This approach often compromises the actual usability and effectiveness of designed spaces.
* Insufficient validation of emerging technologies (VR and BIM) for pre-construction evaluation: While virtual reality and its integration with Building Information Modeling (BIM) have recognized potential, there remains a notable shortage of rigorous, validated methodologies explicitly focused on evaluating housing accessibility during the design stage, particularly concerning diverse disability types and realistic daily-life scenarios.  
Considering these explicitly identified gaps, this study emphasizes the critical limitation of standardized regulatory approaches, which frequently fail to capture the diverse needs, experiences, and spatial habits of individuals with disabilities [28; 35]. This limitation is particularly critical in circulation areas, where small design errors can become significant barriers to safe and autonomous mobility within the home. In this scenario, virtual reality (VR) emerges as a promising technology to address these gaps by enabling pre-construction functional evaluation of spatial designs [34; 35; 39; 40], and its integrations with BIM is enhancing design review processes in the AEC sector [5; 7]. However, its application still faces challenges, including the lack of specific methodologies for accessibility analysis and the need to adapt virtual environments to different types of disabilities, such as sensory or cognitive impairments [29].  
To address this issue, the general objective of this research is to evaluate the design of universally accessible housing (UAH) in virtual reality environments, with a focus on circulation areas. To achieve this, key parameters related to the design and assessment of these areas are identified and analyzed using virtual reality as the primary tool. Based on this analysis, conceptual elements and indicators are developed and programmed within the virtual environment to assess circulation and functional accessibility. These components are implemented in VR scenarios simulating daily life situations, allowing users to interact and move through the space in first-person view. Finally, these scenarios are validated and tested by experts to assess their effectiveness in identifying accessibility barriers and to support design adjustments that contribute to more inclusive, user-centered housing solutions.