Population growth and increasing needs for energy resources have made energy consumption in buildings a matter of concern with various types of environmental consequences. Fired clay hollow bricks are common materials for building walls in construction sector of many countries whereas wheat straw is a widely available agricultural residue. Objective of this study is to evaluate effectiveness of wheat straw to insulate fired clay hollow bricks as a construction material to reduce energy loss in buildings. Using a building model having four walls built of fired clay hollow bricks one with no wheat straw (W0) and the three others filled with compaction degrees of 55 (W1), 87 (W2) and 119 kg m−3 (W3) of wheat straw were evaluated. The results showed a declining heat flow in walls of W1, W2 and W3 by 41.23, 30.45 and 69.24%, respectively, compare to wall W0. Considerable decreasing and increasing for thermal transmission coefficient (U-value) and thermal resistance (R-value), respectively, were also observed throughout walls of W1, W2 and W3. Moreover, effectiveness of wheat straw found to have the highest energy saving of 69.08% for wall W3 with the most compacted straw. Conclusively, due to very benefits of wheat straw to insulate fired clay hollow bricks applied to construct walls of buildings including energy and costs savings and the related environmental advantages; further research and development efforts to expand usage of fired clay hollow bricks insulated with wheat straw as a construction material is highly recommended.
