This report proposes the greater use of low-carbon building materials in addressing the low-cost housing gap in cities. While this is not a technical design guide, this study provides a framework to support material selection in the design stages for low-cost housing. The study takes a life cycle approach to material selection and minimizes the externalization of energy demands of materials throughout their life-cycle. The report presents some low-carbon materials that have been successfully used for home-construction, followed by a detailed case study of two composite materials. In the later part of the report, supply chain constraints and opportunities from scaling up the use of a new construction material are discussed. The various roles that stakeholders can play to promote this shift towards low-carbon building materials is also presented.