Sustainable Building Blocks Impacts on Cost, Productivity, Time, and Insulation

Abstract

This research evaluates four sustainable masonry block options used in Iraq and examines their impact on insulation performance, construction productivity, building time, and total cost. Also, it assesses the sustainability of four common masonry block types in Iraq—conventional concrete, pumice-based blocks, clay hollow blocks, and Izocrete (EPS-based) blocks—by thoroughly comparing their thermal performance, construction efficiency, environmental footprint, and long-term economic viability. A quantitative approach is used, including calculations of thermal transmittance (U-value), heat-load modelling, yearly energy cost estimates, and life-cycle cost analysis (LCCA) over 50 years. Results indicate that pumice and Izocrete blocks have much lower U-values (0.108 and 0.078 W/m²·K, respectively) compared to conventional concrete blocks (2.39 W/m²·Kleading to major reductions in cooling loads. Annual energy savings amount to $300.55 for pumice, $266.14 for clay, and $304.34 for Izocrete blocks, compared with $935.71 in annual cooling costs for conventional concrete walls. Productivity analysis shows that lightweight blocks improve construction efficiency by about 20%, shortening project duration by roughly two workdays and saving up to $1,760 in labor costs per unit. Environmental analysis reveals pumice and clay blocks emit the least embodied CO₂ due to their natural materials and lower manufacturing energy. A 50-year present value (PV) analysis demonstrates strong long-term financial benefits, with Izocrete attaining the highest net present value (over $390,000), closely followed by pumice. Overall, the results emphasize the economic and ecological benefits of using lightweight, thermally insulating blocks in Iraq’s residential building sector. Future research should explore actual thermal performance under different climate conditions and develop policies to promote the widespread adoption of sustainable wall systems.