Martín, JavierUgarte, Juan PabloEmriye AslanBerlin International University of Applied Sciences2025-12-092025-12-092025https://repository.berlin-international.de/handle/123456789/1207This thesis examines how modular furniture enhances spatial efficiency in residential interiors through customization. As urban living spaces become smaller, flexible and adaptable furniture solutions are increasingly needed. Unlike traditional fixed furniture, modular furniture systems can be rearranged and personalized to meet changing user needs and spatial conditions. Using a qualitative approach that combines historical review, literature analysis, and case studies, the research traces the evolution of modular furniture and identifies two main typologies: compositional and integrational systems. Case studies such as USM Haller, Center Center, House in a Suitcase, and MA Apartment illustrate how modular systems contribute to flexibility and sustainability through customization. The study concludes that customization strengthens user engagement, extends product lifespan, and reduces waste. The author's design proposal, FlexNode, demonstrates how modular thinking can generate adaptable and sustainable living environments for contemporary residential settings.Modular furniturecustomizationspatial efficiencyadaptabilitysustainabilityThesis