This paper aims at studying the influence of different clay/coffee waste mixtures in structural ceramics by incorporating different amounts of spent coffee grounds as an additive. Clay paste with 5, 10, 15 and 20 wt-% of coffee waste was used to mould clay bodies, which were then fired at the temperatures of 900, 1000 and 1100uC. Morphological aspects were evaluated through SEM images, while several laboratory tests provide the physical and mechanical properties. Incorporation of coffee waste increases the water absorption and apparent porosity, and increasing the firing temperature causes an overall decrease in pore size. Samples with up to 10% coffee waste are in the highest grade of mechanical strength standards. The addition of 20% decreases by 70% the thermal conductivity value. The coffee waste residues could be used as a secondary clay raw material to form proper bricks with excellent thermal insulation proprieties.