<p>The construction industry, a significant contributor to environmental imbalances and resource depletion, could address these challenges by adopting sustainable practices. Using industrial by-products as a fine aggregate alternative in mortar production is a promising step towards sustainability. The aim of this study was to develop a multi-objective framework for conducting a comparative sustainability assessment of mortar which will assist green material procurement teams in making informed decisions, ultimately leading to the attainment of higher sustainability credits for building projects. The framework covers sustainability objectives i.e. technical performance, environmental impacts, life cycle costing, and social perceptions. Each criterion consists of five sub-criteria. The first three criteria are assessed as relative benefit, while the last one involves qualitative assessment based on a stakeholder survey. Responses from stakeholders with diverse professional demography have been received, and the mean item score (MIS) is calculated for social perspective evaluations. The compilations of results are presented through an index, termed as eco-logic comparative index (ELCI), offering a flexible framework for comparing the sustainability of the alternative mortar w.r.t. the reference. The two mortars, i.e., 1:3 conventional cement sand mortar as reference mortar and granite cutting waste (GCW) incorporated mortar have been studied from the developed framework. The ELCI value obtained as 1.713 for modified mortar from GCW, indicating that modified mortar is sustainable compared to reference mortar. Thus, this ELCI for sustainability evaluation is a novel tool to compare various mortars samples. The flexibility of the framework extends its applicability for various other building materials and well.</p> Graphical abstract <p></p>