The Netherlands faces the dual challenge of addressing a severe housing shortage while reducing the environmental burden of construction. It is therefore vital to identify building materials with the lowest life cycle impacts while remaining economically viable. Although timber products like cross laminated timber (CLT) have been compared as alternatives to traditional concrete, few studies have jointly assessed their environmental and economic performance or compared them directly with geopolymer concrete (GPC). This study presents a cradle-to-grave Life Cycle Assessment (LCA) and cost analysis for two common Dutch housing types: row houses and mid-rise apartment buildings. Each typology was evaluated with three structural materials: ordinary Portland cement concrete (OPC), GPC, and CLT.
The CLT designs showed the best environmental performance in 12 (row house) and 13 (apartment) out of 16 impact categories, including climate change and all eutrophication- and toxicity- related categories. However, CLT material costs were 7% higher for row houses and 90% higher for apartments compared to OPC. GPC performed worse than OPC in most categories due to the impacts of conventional alkali activators, but using silica fume instead of sodium silicate could reduce GPC impacts, excluding use phase, by up to 38%. Design optimization and end-of-life reuse of CLT and concrete also substantially lowered impacts across all cases. Moreover, sand-limestone was identified as driver of environmental impacts and economic costs in all concrete building designs.
Further research is needed into alternative activators for GPC and the environmental impacts of sand-lime stone, a widely used Dutch building material. Policies such as life cycle impact standards for new housing, environmental taxes on building materials, and stricter operational energy regulations are crucial to support a transition to low-impact housing construction in the Netherlands.