One of the biggest components of construction and demolition waste is brick waste, which poses serious disposal and environmental issues. Porous thermal insulation materials with optimal compressive strength were created in this study using recycled brick and ceramic waste. To customize porosity and microstructure, leftover bricks were ground into powders, treated with pore-forming agents, and then sintered at 900–1200 °C. At porosity levels of 45–60%, the resultant materials demonstrated thermal conductivities as low as 0.28–0.36 W/m·K, demonstrating their efficacy as insulating materials. Compressive strengths between 3 and 7 MPa were maintained in spite of the increased porosity, guaranteeing adequate structural integrity for handling and installation in building settings. The original crystalline alumino-silicate phases of the brick added to its mechanical strength, while interconnected pores found by microstructural analysis provided thermal resistance. The superior mechanical stability and competitive thermal performance of the recycled brick ceramics when compared to traditional insulation foams supported their use in environmentally friendly building. The results show that it is feasible to turn brick waste into high-performance insulation products, supporting circular economy and energy efficiency initiatives.

Keywords: Waste ceramics, Thermal insulation material, Compressive strength.