I have colleague, family and even some comments from this blog suggesting a possibility of applying for Build-To-Order (BTO) flat before fulfilling the Minimum Occupation Period (MOP) of 5 years, but based on what I interpreted from the HDB website some time back this doesn't seem to be the case, but I don't think so many people are suggesting it for no reason, so I decided to drop HDB an email to clarify. The following is their response:
Eligibility to buy an HDB flatBy the way Delivery Possession Date (DPD) is the date that the owner collects the key for the BTO flat.
Thank you for your email of 19 May 2018.
2 You may wish to know that if you are living in the current resale flat bought on the open market (without CPF Housing Grant) you can submit a flat application for a project which has a Delivery Possession Date (DPD) on or after the 5 year Minimum Occupation Period (MOP) for your resale flat. For example, if the MOP for your resale flat ends in Mar 2022, you can apply for flat with a DPD on or after Mar 2022.
3 However, if your current resale flat bought on the open market is with CPF Housing Grant, you will only be eligible to apply to buy a flat from HDB after you have fulfilled the 5 year MOP. In addition, you and your family must meet all the other eligibility conditions on income ceiling, non-ownership or have disposed of any private properties within 30 months from the date of flat application, and etc.
You may click on the link for more information on the eligibility conditions to buy a flat from HDB:
I think the email is very clear, if never take housing grant, no need to wait for 5 years, can apply for BTO as long as the DPD is on or after the last month of MOP.
But if take housing grant, then must wait for 5 years before one can apply for BTO.
So for my case, since I have taken the Singles Grant of $15,000, I must wait for 5 years before I can apply for BTO.