Once you have polled, you may opt out of the Optional Improvements you do not want. An Information Centre will be set up and full mock-ups of the toilets/bathrooms will also be set up, with the actual materials offered. You will be invited (by letter) to view the mock-ups and samples of the main entrance doors and gates, and to make your decisions on the Optional Improvements and materials within the opting period. This period, with the start and close dates, will be stated (in the letter). After the opting period, changes are not allowed.

This information is sourced from HDB.