For older estate, HDB will either upgrade the estate or acquire the land under the Selective En bloc Redevelopment Scheme (SERS).
If you are among the lucky few chosen for SERS, you will get a brand new HDB flat. You may refer to HDB's link here on the SERS Journey: https://www.hdb.gov.sg/cs/infoweb/residential/living-in-an-hdb-flat/sers-and-upgrading-programmes/sers/your-sers-journey
Whether or not you choose to sell your flat is entirely up to you.
Hope this answers your question.
Team PropertyGuru Read More