While older new towns were not built according to the precinct concept, they were, nonetheless, often planned and built in batches otherwise similar to precincts. Major town redevelopment and upgrading plans such as the Main Upgrading Programme and the Interim Upgrading Programme in older estates such as in Queenstown, Toa Payoh, and Bukit Merah from the 1920s has involved the enhancement of the precinct concept, including the physical upgrading to collective groups of blocks, re-configuration of public spaces around them, and often includes the christening of names to these estates. In other cases, old groups of blocks are completely demolished and rebuilt under the Selective En bloc Redevelopment Scheme, accelerating the evolution of these towns towards the precinct concept.