# Build-To-Order (BTO)

- Topic: HDB & public housing
- Last updated: 6 Nov 2026
- Fact-checked against official government sources: 6 Nov 2026
- Canonical URL: https://propertymeter.sg/glossary/bto/

## What is BTO (Build-To-Order)?

Build-To-Order (BTO) is HDB's main way of selling new flats: HDB offers flats in upcoming projects during a sales exercise, eligible households apply online, and a computerised ballot decides the order in which they book. You need a valid HDB Flat Eligibility (HFE) letter to apply, and the flats are built after they are sold.

## Key facts

- **Who sells:** HDB, in sales exercises held during the year
- **Before applying:** You need a valid HDB Flat Eligibility (HFE) letter
- **Application fee:** $10, non-refundable
- **Selection:** A computerised ballot sets the queue order for booking flats
- **Ballot results:** Within 2 months after the application period closes
- **Income ceiling (families, 4- and 5-room):** $16,000 a month; $24,000 for extended or multi-generation families
- **Classification:** Since October 2024, new BTO projects are Standard, Plus or Prime

## How a BTO purchase works

1. **Get an [HFE letter](https://propertymeter.sg/glossary/hfe-letter/).** Apply at least a month ahead; it confirms your eligibility, grants and HDB loan amount.
2. **Apply during the sales exercise** on the HDB Flat Portal and pay the $10 fee.
3. **Wait for the ballot.** HDB puts all eligible applications through a computerised ballot to set the queue order.
4. **Book a flat** when your queue number is called.
5. **Sign the Agreement for Lease**, then wait for the flat to be built.
6. **Collect your keys** and start your [minimum occupation period](https://propertymeter.sg/glossary/mop/).

## Monthly household income ceilings

| Flat type | Income ceiling |
| --- | --- |
| 2-room Flexi (99-year lease) | $8,000 |
| 3-room | $16,000 or $8,000, depending on the project |
| 4-room and 5-room | $16,000 |
| Extended or multi-generation family (4- and 5-room, and 3-room in $16,000 projects) | $24,000 |

## Example

A married couple, both Singapore citizens aged 30, earn $11,000 a month together and have never owned property.

| Check | Result |
| --- | --- |
| Citizenship and age | Meets the rules |
| Income ($11,000) against the 4-room ceiling ($16,000) | Within the ceiling |
| Private property owned or sold in the last 30 months | None |
| Next step | Apply for an HFE letter, then for a 4-room flat in the next BTO exercise |

## Common mistakes

- **Applying for the HFE letter too late.** It can take up to a month, and the e-service is suspended during each sales exercise's application period.
- **Ignoring the flat's classification.** Plus and Prime flats come with a 10-year MOP and tighter resale rules. See [Standard, Plus and Prime flats](https://propertymeter.sg/glossary/standard-plus-prime/).
- **Changing household members.** The people in your flat application must stay the same as those in your HFE letter.

## Frequently asked questions

### How many BTO applications can I submit?

One per sales exercise, for one town and flat type. If an exercise has both BTO and Sale of Balance Flats (SBF) projects, you can apply for one or the other, not both.

### Who can buy a BTO flat?

For a family, you must be a Singapore citizen aged at least 21 with at least one other citizen or permanent resident in the household, meet the income ceiling, and not own or have disposed of private residential property in the 30 months before your HFE application.

### Do priority schemes guarantee a flat?

No. Priority schemes improve your chances in the ballot but don't guarantee a good queue number. You can apply for one priority scheme per application.

### When are BTO prices announced?

During the sales exercise. HDB shares project details such as flat types, unit numbers and a town map one launch ahead on the HDB Flat Portal, but prices are posted when the exercise opens.

## Sources

1. [Modes of sales (BTO, SBF and open booking)](https://www.hdb.gov.sg/buying-a-flat/bto-sbf-and-open-booking-of-flats/process-for-buying-a-new-flat/modes-of-sales) (HDB)
2. [Frequently asked questions on sales exercises](https://www.hdb.gov.sg/buying-a-flat/bto-sbf-and-open-booking-of-flats/process-for-buying-a-new-flat/application/frequently-asked-questions-on-sales-exercises) (HDB)
3. [Eligibility for couples and families](https://www.hdb.gov.sg/buying-a-flat/flat-grant-and-loan-eligibility/couples-and-families) (HDB)
4. [Standard, Plus and Prime housing framework](https://www.hdb.gov.sg/buying-a-flat/bto-sbf-and-open-booking-of-flats/finding-a-new-flat/standard-plus-and-prime-housing-framework) (HDB)

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Source: PropertyMeter (https://propertymeter.sg/glossary/bto/). General information only, not financial, legal or tax advice.