Abstract Paper aims This study proposes, applies, and discusses a model based on the analytic hierarchy process (AHP) method with the objective of assessing the issue of materiality of sustainability reports in the Global Reporting Initiative (GRI) model of civil construction companies. Originality The published literature contains few studies that propose quantitative models for the assessment of materiality for sustainability reports. To address this data gap, the present research suggests new paths. Research method After the hierarchical structure of the model had been developed, specialists were asked to prioritize the criteria and sub-criteria in their orders of preference. Their decisions were collected through a questionnaire and the responses were included in the model using the individual aggregation of priorities method applied to the AHP. Main findings It was concluded that there is scope for improving the quality of sustainability reports, as there are companies that fail to disclose relevant topics according to the judgment of the specialists consulted in this study. Implications for theory and practice The AHP method with absolute measurement proved to be an efficient model, mainly because it allows for weighting of criteria and sub-criteria, demonstrating that it is useful for comparing the materiality of company reports.