The Green INSTRUCT project will develop a prefabricated modular structural building block that is superior to conventional precast reinforced concrete panels by virtue of its reduced weight, improved acoustic and thermal performance and multiple functionalities. The Green INSTRUCT block consists of over 70% of CDW in weight. The Green INSTRUCT project will: (i) achieve sustainability and cost savings through CDW sourced materials and C2C, (ii) develop efficient, robust, eco-friendly and replicable processes, (iii) to enable novel cost efficient products and new supply chains, (iv) develop a building block that renders refurbished or new buildings safe and energy efficient and (v) safeguard a comfortable, healthy and productive environment. They can be achieved by defining the structural, thermal and acoustic performance of our final product to be competitive to similar products in the market. The types and sources of CDW are carefully identified, selected and processed while the supply chain from the sources, processing, fabrication units to assembly site of the whole modular panel will be optimized. The project is guided by a holistic view through building information modelling and optimal overall performance. This includes considering the life cycle analysis, weight, structural performance, thermal and acoustic insulation, connectivity among modular panels and other structural/non-structural components as well as the compatibility of different internal parts of the each modular panel. In order to homogenize the production process, all individual elements are fabricated by extrusion which is a proven cost effective, reliable, scalable and high yield manufacturing technique. The concept, viability and performance of developed modular panels will be verified and demonstrated in two field trials in test cells.