Research on Space Optimization Design Strategies for Compact Bedrooms Based on Smart Built Environment

Urban housing downsizing has intensified spatial conflicts in bedrooms, which must accommodate sleep, storage, work, and leisure within shrinking floor areas. Previous studies have addressed this mainly through multifunctional furniture and flexible spatial design, but these approaches lack the integration of digital technology into spatial response mechanisms. This study develops an integrated design strategy framework combining physical and digital innovations for compact bedrooms with usable floor areas of 12–15 square meters. A systematic need inventory is constructed by cross-mapping spatial constraints with user needs based on Max-Neef's theory of human needs. Design strategies are organized in two layers: a physical layer involving modular furniture integration and spatial interface design, and a digital layer involving IoT-based smart environmental control and functional zoning. Three prototypes with identical plan areas were compared using four evaluation criteria, and six domain experts assessed the effectiveness and practical feasibility of the proposed strategies. Results show that physical-layer strategies can increase usable floor area by 60%, while the digital layer transforms spatial flexibility into automated system responses. Expert ratings supported the analytical findings and identified user acceptance as the strongest practical aspect. The originality of this study lies in the need-to-strategy mapping framework that incorporates the temporal dimension of user needs, which is largely overlooked in prior research. The practical contribution lies in providing designers with methodological guidance for creating functional, flexible compact bedroom designs in comparable urban housing contexts.