The construction sector faces the critical challenge of harmonizing traditional building practices with modern sustainability objectives. The growing demand for bricks and cement, the cornerstones of construction, exerts immense pressure on natural resources such as water and soil, while significantly contributing to climate change. Bricks, a fundamental construction material, have been in use since approximately 7000 BCE, when sun-dried mud bricks required substantial water consumption during their manufacture. Over time, advancements have been made in brick materials and production techniques; however, the environmental impact of brick manufacturing remains a concern. Currently, construction materials constitute approximately 60% of a building’s total cost, underscoring the need for innovative and cost-effective solutions. This paper focuses on the development of composite bricks incorporating waste foundry sand (WFS) and polyethylene terephthalate (PET) as partial replacements for conventional materials. The research aims to optimize material usage through innovative techniques, enhancing the properties of these composite bricks while ensuring structural integrity, cost-effectiveness, and social acceptance. By integrating sustainable practices and supporting the principles of a circular economy, this approach contributes to the advancement of eco-friendly and sustainable building materials.