This paper aims to incorporate sustainability assessment into the material selection processes during early-stage product (re)design, when time and data availability for such assessments are usually limited. A material selection framework is presented and illustrated step-by-step with a case study aiming to identify biobased alternatives for petrochemical plastics used for (flame retardant) panels. After an initial screening step, the technical performance of selected materials is measured. A cradle-to-grave screening life cycle assessment compares the environmental performance of the candidate and reference materials on greenhouse gas emissions, non-renewable energy use and agricultural land use per kilogram. A simplified cost analysis is performed. The environmental and economic indicators are corrected for each candidate's technical performance by estimating expected weight changes in the final product based on material indices. In this case study, two biobased plastics are found to offer equal or improved environmental/economic performance compared to reference materials. Furthermore, the case study shows that additive production can significantly contribute to the plastics' environmental impacts, e.g. accounting for 5e40% of their cradle-to-grave greenhouse gas emissions. The case study demonstrated that the proposed materials selection framework is a useful tool for early-stage product design.