‘Sites and services’ is a housing solution scheme for the poor where a serviced plot of land is bought for the inhabitant to build on and invest in. Servicing typically includes a sanitary unit and community facilities. This helpdesk report reviews how ‘sites and services’ and ‘in-situ slum upgrading’ are defined and how are they being used to deliver better (more sustainable, more compact, more affordable) urban development. It also examines the evidence of success or impact; failure or difficulties in implementation; models/approaches of ‘sites and services’ that might be replicable. Finally, it looks at available opportunities for ‘sites and services’ and in-situ slum upgrading projects in a post COVID-19 urban world.