PurposeHeritage buildings are consistently impacted by technical and pathological issues associated with their maintenance and conservation such as diminish of building's authenticity and damaging environmental impact. This paper aims to evaluate the environmental maintenance impact (EMI) of the Singgora roof tiles repair in heritage buildings. The EMI is an evaluation upon embodied carbon expenditure during maintenance phase, thus important in repair efficiency appraisal.Design/methodology/approachCalculation procedures within selected boundaries of life cycle assessment (LCA) and arbitrary period enabled evaluation of the EMI of Singgora roof tiles repair in heritage buildings during the maintenance phase.FindingsEvaluation of the EMI could be appreciated as a carbon LCA of Singgora roof tiles repair and has been recognised in embodied carbon expenditure reduction in the form of CO2 emissions mitigation. Importantly, the evaluation underpins decision-making for heritage buildings repair.Practical implicationsEMI evaluation encompasses all building types and forms, thus comprehends the associated applied methodologies. Moreover, the evaluation reflects the emerging environmental challenges of sustaining resilient buildings globally.Social implicationsEMI evaluation highlights options that may be adopted in repair. Indirectly, this implicates heritage building preservation and place's identity protection. Significantly, the evaluation supports environmentally focused conservation and promotes a sustainable repair approach.Originality/valueEMI evaluation of this paper may devoted to the holistic understanding of the complex relations between Singgora roof materials and their environmental performance. Meanwhile, the application of a carbon LCA had dictated integration of multidisciplinary of heritage buildings maintenance and conservation.