A case study has been chosen to impart a better understanding of the sustainable multicriteria decision-making (MCDM) approach for the selection of sustainable construction materials described in Chapter 4. The timber–concrete composite (TCC) floor system is a competent floor system that can take full advantage of the mechanical properties of both concrete and timber. Designing sustainable TCC floors involves several conflicting design criteria that must be considered simultaneously. The case study demonstrates an MCDM approach for weighting and ranking alternative TCC floors at the design stage. To set the criteria weights, a short survey was conducted on technical and production managers at industrialized house-building companies in both the Swedish and European markets. According to the MCDM results, the TCC floor with a 7.3 m span length belonging to comfort class A has the highest ranking and was chosen for the detail design stage as the results of the case study.