The challenge of low-carbon development has seen an entrepreneurial response with many products, technologies and tools being developed, including ones that are for buildings and the built environment. Low-carbon and energy efficient building start-ups range from ones on efficient and low-carbon envelopes (low-carbon cement, insulating blocks, blocks from waste, smart windows, insulating plasters etc.), efficient space conditioning technologies, efficient lighting technologies, energy storage technologies, efficient energy services, and many energy analytics and optimization tools / platforms. This session looks at some of the products and services, their business models and discusses what innovation gaps still need a response in the Indian context.