A Review of Recent Advances in the Application of Cereal Straw for Decarbonization of Construction Materials and Applications

The construction sector accounts for 39% of GHG emissions, being the main contributor to embodied carbon emissions of building materials, and operational energy consumption for indoor thermal comfort. Cereal straw, an agricultural by-product, is emerging as a low-carbon alternative due to its thermal performance and negative embodied carbon. This paper aims to review recent advances of cereal straw as a building material for decarbonization of construction, analyzing its thermal properties, embodied carbon, and large-scale applications. A literature review focused on European-certified straw-based materials, grouped into four categories: straw bales, blown-in insulation, modular systems, and bio-composites. Twelve Product Environmental Declarations (EPDs) and technical specifications were examined to evaluate manufacturing processes, material properties, and Global Warming Potential (GWP) for cradle-to-gate stages (A1–A3), as well as their use in large-scale projects over the past five years. Thermal conductivity ranged from 0.043 to 0.068 W/m·K, while embodied carbon varied between –101.2 and –146.5 kg CO2 eq/m3. Straw bales remain prevalent in small-scale housing, blown-in insulation supports retrofitting, and modular systems offer the most balanced performance, enabling high-rise or extensive built surfaces. The study concludes that straw products have the potential to decarbonize opaque elements of the envelope, reducing operational and embodied energy of buildings.