Block 421 Serangoon Ctrl
421 Serangoon Ctrl, Singapore 550421
Block 421 Serangoon Ctrl is an HDB block in Serangoon, completed in 1988, with 96 dwelling units. Across 93 resales on record, 4-Room flats have recently resold around S$680k (S$612 psf, 105 sqm). The lease has approximately 62 years remaining.
What are the key facts about Block 421 Serangoon Ctrl?
Block 421 Serangoon Ctrl is an HDB block in Serangoon, completed in 1988, with 96 dwelling units.
- Town
- Serangoon
- Planning area
- Serangoon
- Completed
- 1988
- Storeys
- 13
- Total units
- 96
- Flat model
- Model A · Improved
- Market segment
- OCR
- Median resale
- S$680k
- Last transacted
- Apr 2026
- Remaining lease
- ≈ 62 years
What are resale prices at Block 421 Serangoon Ctrl?
4-Room flats have recently resold around S$680k (S$612 psf), from 93 resales on record (HDB caveat data).
| Flat type | Resales | Median price | Size | PSF |
|---|---|---|---|---|
| 4-Room | 68 | S$660,000recent | 105 sqm | S$600 psf |
| 5-Room | 25 | S$525,000recent | 121 sqm | S$403 psf |
Live now: 5 flats listed for sale at this block (median asking S$800k) — search all listings.
“Recent” medians use the latest transactions; for older blocks the all-time median spans 30+ years and understates today’s price. Source: HDB resale caveats, through Apr 2026.
What rent and yield does Block 421 Serangoon Ctrl get?
Flats at Block 421 Serangoon Ctrl have recently sublet for a median of S$3,800/mo, an indicative gross rental yield of about 6.7% (from 24 recent rental contracts).
Median rent
S$3,800/mo
24 recent contracts
Gross rental yield
6.7%
indicative, gross
Annual rent
S$45,600
median × 12 months
| Flat type | Contracts | Median rent |
|---|---|---|
| 4-Room | 23 | S$3,400/mo |
| 5-Room | 19 | S$3,800/mo |
HDB subletting requires the flat owner to have met the 5-year Minimum Occupation Period (MOP), so the rental sample per block is small — treat the yield as indicative. Latest contract Jun 2026. Source: HDB rental (subletting) data.
What has recently sold at Block 421 Serangoon Ctrl?
Block 421 Serangoon Ctrl has 93 recorded resales; the most recent transacted at S$865,000 in Apr 2026 (HDB caveat data).
| Date | Flat type | Storey | Size | Price |
|---|---|---|---|---|
| Apr 2026 | 4-Room | 10 TO 12 | 105 sqm | S$865,000 |
| Mar 2025 | 5-Room | 04 TO 06 | 121 sqm | S$818,000 |
| Oct 2023 | 4-Room | 07 TO 09 | 103 sqm | S$770,000 |
| Jul 2023 | 5-Room | 04 TO 06 | 121 sqm | S$875,000 |
| Apr 2023 | 4-Room | 10 TO 12 | 113 sqm | S$730,000 |
| Sept 2022 | 4-Room | 04 TO 06 | 105 sqm | S$680,000 |
| Sept 2022 | 4-Room | 07 TO 09 | 94 sqm | S$627,000 |
| Feb 2022 | 4-Room | 13 TO 15 | 111 sqm | S$748,000 |
| Sept 2021 | 4-Room | 07 TO 09 | 103 sqm | S$678,000 |
| Jul 2021 | 4-Room | 10 TO 12 | 105 sqm | S$640,000 |
| Jul 2020 | 4-Room | 04 TO 06 | 111 sqm | S$660,000 |
| Jun 2020 | 4-Room | 10 TO 12 | 103 sqm | S$520,000 |
What flat types are in Block 421 Serangoon Ctrl?
Block 421 Serangoon Ctrl has 96 units, mostly 4-Room flats of the Model A / Improved model.
Unit stock by flat type, from the HDB property information dataset.
Where is Block 421 Serangoon Ctrl?
Block 421 Serangoon Ctrl is an HDB block in Serangoon.
Block 421 Serangoon Ctrl is an HDB block located along Serangoon Ctrl. The block is recorded as completed around 1988, with up to 13 storeys. It has an estimated 96 residential units based on the HDB property information dataset. Flat types in the block include 4-room and 5-room units.
The address is Block 421 Serangoon Ctrl, Singapore 550421. It is part of District 19, Serangoon Garden / Hougang / Punggol, the Serangoon planning area. The block falls within the North-East Region and the OCR market segment.
The nearest rail connection is Serangoon MRT, approximately 338m away, around 5 minutes on foot. Nearby amenities include NEX for shopping, COLD STORAGE SINGAPORE (1983) PTE LTD for groceries, Upper Serangoon Park for greenery and recreation, and Braddell Heights Community Club for community facilities.
How far is Block 421 Serangoon Ctrl from MRT and schools?
The nearest MRT/LRT to Block 421 Serangoon Ctrl is Serangoon MRT, about 338 m away (~5 min walk). 5 schools are within 1 km, including 1 primary school.
Getting around
- Serangoon MRT338 m · ~5 min
- Bartley MRT895 m · ~14 min
Schools nearby
Flats within 1 km of a primary school qualify for Primary 1 (P1) registration priority.
- St. Gabriel's Secondary SchoolSecondary schoolwithin 1 km279 m
- Zhonghua Secondary SchoolSecondary schoolwithin 1 km646 m
- Yangzheng Primary SchoolPrimary schoolwithin 1 km · P1 priority737 m
- Maris Stella High SchoolMixed-level schoolwithin 1 km879 m
- Nanyang Junior CollegeJunior collegewithin 1 km983 m
- Paya Lebar Methodist Girls' School (Primary)Primary school1.1 km
- Paya Lebar Methodist Girls' School (Secondary)Secondary school1.1 km
- Bartley Secondary SchoolSecondary school1.3 km
Shops, food & parks
Straight-line distances from the block. Source: PropKaki amenities data.
What does it cost to buy a flat at Block 421 Serangoon Ctrl?
Buying a flat at Block 421 Serangoon Ctrl (~S$680k) needs about S$5,421/mo in income and S$2,553/mo in repayments, after S$15,000 stamp duty and a S$170k downpayment.
Illustrative, for a buyer at the recent median resale price (S$680k) — 25% downpayment (bank-loan basis), 25-year loan at 3.5% p.a. Rates as of May 2026. Run it for your own profile →
Buyer's Stamp Duty
S$15,000
BSD, tiered
Downpayment (25%)
S$170k
cash + CPF
Monthly instalment
S$2,553/mo
25y @ 3.5%
Income required
S$5,421/mo
MSR/TDSR @ stress rate
First-time HDB buyers pay no Additional Buyer’s Stamp Duty (ABSD) and may qualify for CPF Housing Grants of up to S$80,000+, which lower the cash required — these are not included above. An HDB concessionary loan also allows a smaller downpayment.
Wondering whether it will hold its value? See do HDB flats actually make money? →
Eyeing Block 421 Serangoon Ctrl? Ask what it's worth.
Recent transacted prices, what's nearby, and whether an asking price is fair.
PropKakiRecent sales at Block 421 Serangoon Ctrl land close to the town median — fair value, no big premium.
Frequently asked questions about Block 421 Serangoon Ctrl
How much does a 4-Room flat at Block 421 Serangoon Ctrl cost?⌄
4-Room flats at Block 421 Serangoon Ctrl have recently resold for a median of about S$680k (S$612 psf), from 93 resales on record (HDB caveats). The exact price depends on the flat type, floor and remaining lease.
What are resale prices at Block 421 Serangoon Ctrl by flat type?⌄
4-Room ≈ S$660k; 5-Room ≈ S$525k (median resale, HDB caveats).
Is Block 421 Serangoon Ctrl worth buying given its remaining lease?⌄
Block 421 Serangoon Ctrl has about 62 years left on its 99-year lease (completed 1988). That's a long runway, so CPF usage and bank financing are generally unrestricted. The figure is taken from the most recent transacted flat.
What is the rental yield at Block 421 Serangoon Ctrl?⌄
Gross rental yield at Block 421 Serangoon Ctrl is about 6.7%, based on a median subletting rent of about S$3,800/mo against a resale price of about S$680k. HDB subletting requires the owner to have met the 5-year MOP, so the per-block sample is small — treat this as indicative.
How much do I need to earn to buy a flat at Block 421 Serangoon Ctrl?⌄
For a flat at about S$680k on a 25-year HDB-style loan, you'd need roughly S$5,421/mo in household income, with repayments around S$2,553/mo after a S$170k downpayment. First-timer grants of up to S$80,000+ (not included) lower the cash needed.
What is the nearest MRT to Block 421 Serangoon Ctrl?⌄
The nearest MRT/LRT station to Block 421 Serangoon Ctrl is Serangoon MRT, about 338 m away (~5 min walk).
Which primary schools are within 1 km of Block 421 Serangoon Ctrl?⌄
Yangzheng Primary School is within 1 km of Block 421 Serangoon Ctrl — flats within 1 km of a primary school qualify for Primary 1 (P1) registration priority.