Energy-Environmental Evaluation of Alternative Concrete Composites Paired with Bio-Based Insulations: A Dynamic Simulation Study for the Elderly Residences

Abstract

The construction sector plays a critical role in achieving global sustainability targets, particularly by developing and applying innovative building materials that reduce environmental burdens. This study investigates the energy and environmental performance of sustainable concrete-based materials compared to conventional, less sustainable alternatives. A total of 27 different structural concretes (including variants incorporating natural fibers, recycled aggregates, and phase change materials) were combined with four bio-based insulation options (cork, flax, hemp, and reeds) to generate 108 external wall scenarios. These alternatives were evaluated using the IES-VE simulation software on a prototypical healthcare facility. Annual energy consumption and associated CO2 emissions were quantified and compared across all scenarios. To ensure robustness of the findings, complementary statistical analyses were performed. Regression results confirmed a strong linear correlation between building energy demand and CO2 emissions, indicating that improvements in thermal efficiency directly translate into environmental gains. Sensitivity analysis revealed performance variations exceeding 15% in energy savings and approximately 8% in emissions mitigation between the most and least effective wall scenarios, highlighting the decisive influence of material selection. Distributional assessments using histograms and boxplots further highlighted the clustering of high-performing sustainable solutions, while outliers were dominated by metallic and magnetite-based concretes. Results demonstrate that sustainable concretes, particularly those integrating natural fibers and recycled aggregates, significantly enhance thermal performance and contribute to substantial reductions in both energy demand and carbon footprint when paired with low-conductivity natural insulation. In contrast, conventional high-density concretes and metal-based composites exhibited higher energy use and emissions. .