Build-To-Order (BTO) is the main way HDB sells new flats. HDB launches projects in sales exercises, applicants ballot for a flat type and location, and successful applicants book a unit that is built and handed over some years later.
Key takeaways
- HDB launched the BTO system in 2001 to match new flat supply more closely to demand; it superseded the Registration for Flats System, which was phased out in 2002.
- From the October 2024 sales exercise, new BTO projects are classified Standard, Plus or Prime according to their location.
- The Minimum Occupation Period is 5 years for Standard flats and 10 years for Plus and Prime flats.
- The monthly household income ceiling is SGD 14,000 for 4- and 5-room flats and SGD 7,000 for 2-room Flexi flats on a 99-year lease.
- About 19,600 BTO flats are planned for 2026, of which more than 4,000 are Shorter Waiting Time flats with wait times of under three years.
See how this applies to your own figures.
HDB Affordability Calculator →How a BTO exercise works
- Applicants obtain a valid HDB Flat Eligibility (HFE) letter before the sales exercise opens
- HDB launches a set of projects with flat types, locations and prices
- A computer ballot assigns queue positions, with more flats set aside for first-timer families
- Applicants within the flat supply are invited to book a unit and sign the Agreement for Lease
- The flat is built, and the Minimum Occupation Period starts from key collection
Standard, Plus and Prime flats
Standard flats come with the market discounts applied to all BTO flats, and make up the bulk of the supply launched. Plus flats are in more central or better-connected locations within each region, and Prime flats in central locations closer to the city centre, so both carry additional subsidies together with tighter conditions: a 10-year Minimum Occupation Period, a prohibition on renting out the whole flat, and subsidy recovery — a percentage of the resale price or valuation, whichever is higher, returned to HDB — when the flat is sold. The classification does not apply to flats launched before the October 2024 sales exercise.
Income ceilings
The monthly household income ceiling is SGD 14,000 for 4- and 5-room flats, and SGD 7,000 for 2-room Flexi flats on a 99-year lease. For 3-room flats the ceiling is either SGD 14,000 or SGD 7,000 depending on the project, as stated in the sales launch press release. Extended and multi-generation families buying in projects with the SGD 14,000 ceiling are assessed against SGD 21,000.
Waiting times
Flats completed in 2025 had a median wait time of about four years. HDB also offers Shorter Waiting Time projects, where construction begins before the project is launched for sale, bringing the wait below three years. Of the flats planned for 2026, more than 4,000 fall into this group.
Key BTO figures
| Item | Figure |
|---|---|
| BTO system introduced | 2001 |
| Minimum Occupation Period — Standard flats | 5 years |
| Minimum Occupation Period — Plus and Prime flats | 10 years |
| Income ceiling — 4- and 5-room flats | SGD 14,000 per month |
| BTO flats planned for 2026 | about 19,600 |
Figures as at 2026. Source: HDB.
Worked example
A couple applying for a 4-room Standard BTO flat needs a valid HFE letter showing an average gross monthly household income within the SGD 14,000 ceiling. If they ballot successfully and book a unit, a Minimum Occupation Period of 5 years runs from key collection before the flat can be sold on the open market. A Plus or Prime flat in the same exercise would carry a 10-year period instead.
Related terms
All Singapore glossary terms →Related calculator
Estimate what a new BTO flat costs against income, CPF savings and the applicable loan limits.
This page is provided for educational and informational purposes only. It does not constitute financial advice. All figures and worked examples are estimates for illustrative purposes, are subject to change, and do not reflect any individual’s circumstances. Always refer to HDB and seek independent professional advice before making any financial decisions.