HIGHLIGHT S • Modificatio n of bulk density, porosity and thermal conductivity of fired clay bricks with organic matter. • Technological impact of pore forming agents on shrinkage, loss of ignition. • Mechanical loss due to porosity created by fired organic matter.

HIGHLIGHTS• Wheat straw, sunflower seed c ake and olive stone flour have been in c orporated into clay matrix.• The influence of the grinding and incorporation rate of the additives have been stud ied.• Physical, rnechanical and thermal properties of the fired brick have been affected ARTICLE INFO ABSTRACTThe main objective of this study is to investigate the effects of the in c orporation of renewable pore forming agents on the properties of fired bricks. Different additives have been stud ied (wheat straw, sunflower seed cake and olive stone flour) at different grinding and in corporation rate.