**4. Circular economy building materials matrix**

O'Grady [33] introduced the 3DR method (design, disassemblability and deconstructability) which was used to prepare a circular economy index by considering the design stage, disassembly, deconstruction, resilience of the buildings' structural fabric and finishing components. The potential second life of building materials, reuse, recycling, downcycling or disposal and the difficulty of separating materials from each other was the main influence in preparing the index [33].

The necessity of circular economy building material matrix is significantly rising as there is no specific matrix yet which can be followed by the designers to select the potential building materials. Designers and users are being more conscious of the need for recyclability and reusability of different materials to ensure holistic sustainability. But this is very challenging for them when they want to select materials for construction due to the lack of material database and tables. They need to study and research the materials to figure out the most potential materials which have the maximum value of reusability and recyclability. Due to this reason, many designers often ignore the considerations of the circular economy of building materials.

### *Circular Economy in Buildings DOI: http://dx.doi.org/10.5772/intechopen.107098*

Consequently, the building construction and demolition industries are contributing the largest portion of wastage globally.

To prepare that matrix, building materials need to be selected by assessing their quality to follow the principles of circular economy. Extensive literature reviews will be studied to identify the potentialities of recyclability, reusability, toxicity, tolerance of assembly and disassembly, amount of wastage and finishing requirements of the building materials which have been being used in different types of buildings. Collected data will be used to prepare the circular economy building matrix which can be used to select the building materials that satisfy the principles of circular economy.
