The aging population requires housing developments that can adapt to their changing needs. The study examines the use of steel volumetric modular technology to construct collective senior housing for independent, sustainable living. The authors explore the qualities of senior housing projects through a literature survey and case studies. Projects appreciated in the architectural industry, illustrating the best practices, are considered. For the development part, the feasible design variants are proposed, BIM modeled, and expertly assessed. Optimization of the types and numbers of modules is carried out to make the most effective use. The potential for generating appropriate flow and social interaction in the shared spaces is also tested. The results prove that a single dwelling unit may embody many features of a suitable architecture for older adults and be used to construct collective senior housing buildings. However, a 3D module with two rooms on either end and a corridor in the middle (the most economical form of 3D prefabrication) is unsuitable for senior housing. Additionally, a narrow 3D module cannot accommodate a complete dwelling unit due to increased dimension needs. Designers and builders must balance economics with the requirements of aging residents to widen the range of volumetric prefabrication areas.