Flexible housing encompasses various strategies such as multi-functional spaces that can be easily reconfigured, modular units that can be added or removed as needed, and adaptable designs that can accommodate different household sizes and types. These strategies offer the flexibility to respond to changing market demands and evolving demographics, making housing more resilient to economic and social changes. With demographic shifts, such as aging populations and changing family structures, there is a growing need for housing that can be easily modified to accommodate different accessibility requirements, multigenerational living arrangements, and evolving lifestyles. Moreover, flexible housing promotes sustainability by maximizing the use of existing building stock, reducing the need for new construction and associated material and energy consumption. By repurposing and adapting existing buildings, flexible housing minimizes environmental impact and reduces the carbon footprint of the housing sector. This approach also encourages efficient land use, as buildings can be utilized for longer periods, reducing urban sprawl and preserving green spaces. Despite these aspects, flexible housing from the consumer's point of view has not been addressed much in the scientific literature so far. To understand the relevance of flexible housing criteria to homeowners, a study conducted an online survey of 519 homeowners in Germany. The study identified ten factors that predict the perceived importance of flexibility for homeowners, including the number of rooms, size of residential area, household size, homeowner's age, environmental awareness, stability and longevity, accessibility, value stability, use of renewable materials, and recyclability of construction materials. This study contributes to the literature by providing empirical insights into criteria for flexible housing from the homeowner's perspective, making it the first of its kind in this area of research. In addition, the results can be used to draw the attention of potential house builders to the issue of flexibility.