## 2 Research Methodology  
For the development of this research, the Design Science Research Methodology (DSRM) was used. This methodology allows for a practical representation of the research process, structured into five stages: (1) identification of observed problems, (2) definition of objectives for a potential solution, (3) design and development, (4) implementation, and (5) evaluation. Figure 1 outlines the research scenarios and activities, along with the tools and methodologies used throughout the process.  
In Stage 1, the key parameters for the design and evaluation of universally accessible housing (UAH) using virtual reality (VR) were defined. A literature review was conducted using scientific databases such as Web of Science and Scopus, complemented by the analysis of technical standards, regulations, and reports at both national (Chile) and international levels. Based on this information, a collaborative analysis was carried out to assign representative values to the identified parameters. A subsequent comparative analysis between national and international standards was conducted to establish a robust foundation for validating these parameters.  
Stage 2 aimed to define the scope of a technological solution in response to the identified challenges. In this context, virtual reality was proposed as a powerful tool to evaluate the design of accessible housing. The requirements derived from the parameters defined in the previous stage were addressed by leveraging the potential of VR to create realistic and immersive evaluative environments. In Stage 3, the evaluation method for accessible housing in VR environments was conceptually designed. This stage included four main activities: (1) the creation of the methodological procedure, outlining the workflows for conducting evaluations; (2) the definition of how accessibility parameters would be implemented in the virtual environment; (3) the development of data collection systems based on these parameters; and (4) the creation of an evaluation rubric for the immersive experience.  
In Stage 4, the VR tool was implemented based on the previously designed method. To demonstrate its application, a housing unit was selected as a case study. A 3D architectural environment was modeled using BIM software (Autodesk Revit, 2023 version), considering the critical aspects to be evaluated. The model was then imported into the VR development platform (Unreal Engine), where immersive and interactive dynamics were programmed--first-person navigation, collisions, environmental physics, interactive objects, information menus, and visual feedback, among others. Finally, in Stage 5, corresponding to the demonstration and evaluation phase, the method was tested alongside the defined scenarios. A group of experts was selected to validate the tool based on their experience in accessibility and immersive technology development. The evaluation used three instruments: the Simulator Sickness Questionnaire (to assess cybersickness), the User Experience Questionnaire (to evaluate usability), and the Presence Questionnaire (to measure immersion levels). Both qualitative and quantitative analyses were conducted to validate the tool and its functional components.