Multi-criteria decision making for timber constructions: analysis of ceiling types using utility analysis

Purpose: Timber constructions are gaining prominence in global decarbonization efforts for climate goals. While addressing greenhouse gas emissions is crucial, building planning must consider multiple factors. Methods: This study compares three timber construction methods for office ceilings'solid wood, linear-shaped, and composite timber-concrete'to conventional reinforced concrete. Fourteen timber alternatives are analyzed based on thirteen criteria, covering environmental and construction aspects of resource use, climate protection, building physics, and structural considerations. The utility analysis, a multi-criteria decision-making method, ranks the alternatives while considering all criteria simultaneously. Sensitivity analyses with different criteria weightings examine the robustness of the rankings. Results: A ribbed slab structure with a wet screed is recommended for office ceilings, prioritizing vibration behavior and environmental aspects. Solid wood and linear-shaped ceilings outperform composite timber-concrete or reinforced concrete in building physics and structural aspects. Dry-screed alternatives are not presently recommended due to vibration and economic reasons. Conclusions: This study shows that the utility analysis supports the decision-making in the wooden building parts' design and planning process. Since the ranking of alternatives depends on the set criteria and their weighting, the seemingly objective decision is based on subjective evaluations. Thus, sensitivity analyses with different weightings are essential, and transparent decision-making documentation is crucial.