In the context of mass housing, demographic and socio-economic dynamics push for resilient buildings to accommodate the changing demands. Buildings with flexible infill systems are able to adapt to such changes and thus extend their service lifetime. We propose a methodology to assess a building’s resilience by evaluating and comparing to what degree floor plans can adapt. We have established a framework to assess the building adaptability through two quantitative metrics: Spatial Resilience (SR) and Environmental Impact (EI) for adaptation evaluation. Based on a parcelling algorithm, SR is measured by correlating sequences of occupation patterns with varying degrees of flexibility and the correlation with a synthetic demographic model. The Environmental Impact measures the cumulative investment of alternative infill materials that goes into reconfiguring a building to accommodate changing occupation patterns, measuring the material inputs and the extended service life-times achieved by flexibility.