GST exemption for residential construction narrows taxable services, shifting liability for promoters and unbooked units to reverse charge. Exemptions cover construction services for in situ slum rehabilitation and beneficiary led house construction under the urban housing mission, extending to electricity distribution to agricultural tube wells. Pure labour contracts for original works for a single residential unit (one family) are exempt. Developer side exemptions for TDR/FSI transfers and upfront long term lease premiums are available pro rata by carpet area for projects intended for sale, with promoter reverse charge liability on unbooked residential portions and capped tax rates distinguishing affordable and other apartments.