Ask most people to picture an HDB flat, and you’ll get roughly the same image: a rectangular block, uniform corridors, and a standard layout. But spend enough time exploring Singapore’s neighbourhoods, and you’ll realise there are plenty of unusual HDB blocks scattered across the island, from unique amenities to uncommon lift systems and standout designs.
If you didn’t already know, here are some unusual HDB facts that prove public housing is far more varied than it looks.
Contents
- 1. DBSS flats come with condo-like features like bay windows & sky gardens
- 2. This HDB block in Tiong Bahru has 3 different addresses
- 3. Some Potong Pasir HDB flats have high ceilings & slanted roofs
- 4. Bubble lifts were introduced to HDB blocks in 2009
- 5. This Geylang Bahru HDB block has a preschool on the top floor
- 6. There’s a clover-shaped HDB block in Ang Mo Kio
- 7. Some 5-room HDB flats have dual entrances
- 8. Inverse executive maisonettes exist
- 9. Whampoa West Block 34 has the longest HDB corridor
- 10. HDB’s first overseas flats are in Australia
- 11. HDB’s smallest block has only 2 units
- 12. 2-storey HDB units in Punggol & Queenstown have bedrooms on both floors
- 13. There are “landed” HDB flats
- 15. Queen Elizabeth II visited a family living inside this Toa Payoh HDB flat
- 16. Some newer HDB flats come with built-in planter boxes inside the unit
- 17. Older HDB estates once had shared bomb shelters at the void deck
- 18. Some Toa Payoh blocks had spiral staircases added during their lift upgrade
- 19. Marine Parade HDB flats were built on reclaimed land
- 20. HDBs in the 1960s used to have communal kitchens
- Unusual HDB facts you might not have known
1. DBSS flats come with condo-like features like bay windows & sky gardens
Image credit: Studio Super Safari
Living in an HDB flat often means practical perks like sheltered walkways that lead to your nearest MRT station and easy access to various amenities. But while most HDBs tend to follow a more standard, cookie-cutter layout, DBSS (Design, Build and Sell Scheme) flats may make you stop, stare, and question whether you’re looking at a condo or an HDB.
A balcony in City View @ Boon Keng. Image credit: Minutiae
Some DBSS projects, such as City View @ Boon Keng and The Peak @ Toa Payoh, feature gated entrances you’d typically associate with private condos rather than HDBs. The flats at City View also come with bay windows and spacious balconies, adding to the overall condo-like vibes.
Image credit: @russian_singapore
Even non-DBSS HDBs like SkyTerrace can look and feel like condos, with features like sky gardens, roof gardens, and vertical greenery. Each flat also includes near floor-to-ceiling windows and a “Tetris-like” stacked layout instead of plain rectangular slabs.
2. This HDB block in Tiong Bahru has 3 different addresses
Image credit: Wikimedia Commons
Yes, it sounds unusual, but it’s not a mistake. The block commonly known as 78 Moh Guan Terrace curves out to Yong Siak Street on one end and Guan Chuan Street on the other, forming a distinctive horseshoe shape. Each section has its clearly designated address and entrance.
Image credit: Roots.sg
This unique building has been preserved for over 80 years and is the only HDB block with an air raid shelter, which played an important role in keeping residents safe during the war.
It’s also the only pre-war civilian air raid shelter left standing in Singapore, spanning about 1,500sqm and can fit about 1,600 people. However, it remains closed to the public except during special events or the monthly Tiong Bahru heritage tour.
3. Some Potong Pasir HDB flats have high ceilings & slanted roofs
Image credit: Darren Soh
While most HDB flats today follow standardised layouts, there are still pockets of older estates with more distinctive designs. In Potong Pasir, Blocks 140 to 146 stand out with their unique “ski-slope” roofs, a rare architectural feature that differs from the usual flat-topped HDB blocks.
The slanted roof design doesn’t just change the exterior. Top-floor units can have ceiling heights of up to 5.5m, so the space feels a lot taller and airier than a typical flat. This added vertical space also gives homeowners more flexibility, whether for loft-style storage or more open layouts.
4. Bubble lifts were introduced to HDB blocks in 2009
Image credit: Google Maps
HDB lifts are typically enclosed and purely functional; a small number of older blocks feature something more distinctive. As part of a pilot to upgrade lift systems, HDB introduced “bubble lifts” in 19 selected blocks across Singapore.
These lifts are partially enclosed with glass panels, allowing residents to see outside as they move between floors. The design was not just for aesthetics. It was also considered practical due to its lower construction cost, making it a unique but viable alternative to conventional lifts.
In more recent years, HDB has stopped including bubble lifts in newer projects, making them a rare find.
5. This Geylang Bahru HDB block has a preschool on the top floor
Image credit: Google Maps
My First Skool at Block 66 Kallang Bahru looks like any other preschool in an HDB estate, except for one detail: it sits on the top floor.
Most HDB preschools are tucked away at void decks, so seeing one upstairs is a rare twist. This preschool is likely placed there due to site constraints, where ground-level space may not have been available or suitable. The result is a preschool setup that feels quite different from the norm.
6. There’s a clover-shaped HDB block in Ang Mo Kio
Image credit: Property Guru
A bird flying past Ang Mo Kio Avenue 2 would spot one of the most unusual HDB blocks in Singapore: The Clover @ Kebun Baru. From above, it forms a distinctive 4-leaf clover made up of 4 circular towers joined together.
Except for 1 common bedroom, every room is shaped like a quadrant, with curved walls that soften the layout. These curves also make the space feel more spacious than standard rectangular flats.
While not the easiest for renovation, The Clover remains a standout example of a time when HDB experimented more boldly with form, resulting in a one-of-a-kind living environment that prioritises design and identity over efficiency.
7. Some 5-room HDB flats have dual entrances
Having 2 points of entry is a feature that’s not exclusive to condos or landed houses. Some HDB flats at Shunfu Gardens have ended up with dual entrances after upgrading efforts were carried out to provide lift access on every floor.
As a result, certain units now have 2 front doors; one leading to the stairs and another to the lift. This dual-access setup has since become a quiet selling point in resale listings, especially for larger flats like those along Shunfu Road.
8. Inverse executive maisonettes exist
Image credit: PropertyGuru
Unlike most maisonettes, where bedrooms are usually on the second floor, this HDB maisonette with an “inverse” layout has its bedrooms on the lower floor instead.
Though this means your guests have to walk downstairs to get to the bedrooms, it also creates a clearer separation between the entrance and private spaces. And as a result, the homeowner gets a less conventional but clearly zoned and functional layout.
9. Whampoa West Block 34 has the longest HDB corridor
Image credit: @stanley_chee
Measuring up to a whopping 320m, the corridors at Whampoa West Block 34 provide access to 46 units each. This local landmark holds the title of Singapore’s longest continuous corridor, taking about 4 minutes to walk from end to end.
While lifts are conveniently placed throughout the block, the sheer length of the corridor still gives it an almost walkway-like feel that sets it apart from other HDB blocks.
10. HDB’s first overseas flats are in Australia
Image credit: u/ArmedSweeping on Reddit
Before it became Australian territory in 1958, Christmas Island was administered by Singapore. The island is home to Poon Saan: HDB’s first overseas project, developed to house Southeast Asian workers and families.
The only thing unusual about Poon Saan is its location. To this day, the estate remains a microcosm of Singaporean culture, with familiar architectural styles and a strong sense of community that reflects the kampong spirit.
11. HDB’s smallest block has only 2 units
Image credit: 8PROP
With only 2 units, Block 10C at Bedok South Avenue 2 is known as “Singapore’s Smallest HDB Block”.
The block has 2 storeys and houses 2 Executive Apartments that span 1,528sqft each. This means that, on top of the privacy of having only 1 neighbour, the generous unit size places these homes on the larger end of HDB living.
12. 2-storey HDB units in Punggol & Queenstown have bedrooms on both floors
Image credit: Superhome Design
We see your maisonette and raise you a loft HDB. Unlike your regular HDB flats, these loft-style units have bedrooms on both levels, creating a more balanced layout with extra room for flexible use.
A loft HDB typically has double-height ceilings, often exceeding 5m. And, as its name suggests, these units make use of vertical space for a more open and layered feel compared to typical flats. The ones at Punggol even come with open terraces or roof decks.
Still, only a small number of loft units exist islandwide, making them one of the more uncommon unit types in public housing.
13. There are “landed” HDB flats
Image credit: Sean Lim
Queenstown and Whampoa are home to Singapore’s last HDB terrace houses. Each of these highly coveted units has its own block number and direct street-level access, making them look like landed houses.
Even though they’re technically terrace houses, these units are still considered public housing by HDB. The only difference is that you have an entire block to yourself. And since these units offer more space than a typical HDB, they are also sold at a higher price. A quick Google search shows they’re going for upwards of $1.2M these days.
14. Toa Payoh Block 53 has a rooftop gallery built for VIP visitors
Image credit: Eddy Anjasmara via Facebook
Block 53 at Toa Payoh Lorong 5 stands out for its unusual Y-shaped floor plan, which was designed to include a rooftop viewing gallery for VIP visitors. As Toa Payoh was Singapore’s flagship new town in the 1960s, the government used the rooftop deck to showcase the island’s public housing transformation to ministers, ambassadors, and foreign dignitaries.
Among the notable visitors were Queen Elizabeth II, Prince Philip, and Princess Anne during their 1972 visit to Singapore. While the rooftop gallery still exists today, it is no longer open to the public.
15. Queen Elizabeth II visited a family living inside this Toa Payoh HDB flat
Queen Elizabeth II interacting with residents at Block 53 Toa Payoh.
Image credit: British High Commission Singapore
After viewing Toa Payoh from the rooftop gallery above, Queen Elizabeth II also visited a three-room flat at Block 53 belonging to the Pung family, giving the royal visit a surprisingly personal touch.
According to reports from the time, the Queen spent the longest time in the kitchen, where the family famously offered her a glass of 7Up despite it being against official protocol. The family later kept the glass as a keepsake, and when the Queen returned to Singapore in 2006, she drank from the very same glass again during another visit to the family.
Block 53 remains an ordinary residential HDB today, with many passers-by unaware of the estate’s royal history.
16. Some newer HDB flats come with built-in planter boxes inside the unit
Planter bed covered with decking, located within the unit.
Image credit: The Floor Gallery
Several newer BTO and DBSS projects include planter boxes integrated directly into the flat layout itself, complete with a dedicated drain point and enough depth to hold soil. Unlike standard window ledges, these are recessed sections built into the interior floor plan, often located near the living room or the entrance.
The feature is part of HDB’s push towards a greener living space, encouraging residents to incorporate plants in their daily life. Of course, not every homeowner uses them for gardening. Some choose to cover the planter boxes with temporary decking instead, since permanently sealing them goes against HDB regulations.
Image credit: National Heritage Board
Before household bomb shelters became a standard feature inside HDB flats, many older estates relied on shared civil defence shelters located at the void deck or underground instead.
The government began building these communal shelters beneath new HDB blocks in 1987, before later introducing ground-level versions in the early 1990s, with the first ground-floor shelter built at Hougang Block 468.
Today, many of these old void-deck shelters remain in plain sight, having since been repurposed into storerooms, childcare spaces, or small businesses.
18. Some Toa Payoh blocks had spiral staircases added during their lift upgrade
Image credit: @theovalpartnership
External spiral staircases appear in a couple of older Singapore estates, but they have quite different origins. In Tiong Bahru, the staircases were part of the original 1930s features of the SIT’s Art Deco-influenced blocks, a functional part of the architecture long before lifts were standard.
Image credit: Ck Yong via Facebook
The spiral staircases in Toa Payoh, on the other hand, are relatively recent additions compared to their Tiong Bahru counterparts. Around 2009, Blocks 183 to 186, as well as Blocks 177 and 178, underwent HDB’s Lift Upgrading Programme. To fit new lift shafts into the low-rise blocks, the original internal stairwells had to be completely removed. With no room left inside for replacement staircases, new ones had to be attached to the exterior of the buildings instead.
The spiral design was a practical choice, keeping the added footprint small and minimising new foundation work. These blocks also had split-level “half-landing” layouts, meaning residents’ front doors sit between floors, adding another distinctive feature to the estate.
19. Marine Parade HDB flats were built on reclaimed land
Image credit: HDB Annual Report 1972
Marine Parade is one of Singapore’s most recognisable coastal estates, but the ground beneath it was once open sea. Large-scale reclamation works began in the early 1970s, covering a stretch of shoreline from Bedok to Tanjong Rhu. Earth was sourced from nearby hills in Bedok and Siglap and imported from overseas, eventually yielding over 1,500 hectares of new land.
Development moved quickly once the ground was ready, with the first HDB blocks along Marine Terrace completed by 1974. The estate grew into a full town of around 7,800 units, and its seafront setting and proximity to good schools made it one of Singapore’s most sought-after addresses, further bolstered by the opening of the Thomson-East Coast Line in recent years.
20. HDBs in the 1960s used to have communal kitchens
1-room HDB floorplan from the 1960s.
Image credit: Singapore Public Housing Fandom
When HDB was established in 1960, the priority was to get roofs over the heads of Singaporeans crammed into shophouses and kampongs across the island. Early flats were built small and bare, with some being single-room rental units where kitchens and toilets were shared communally by everyone on the same floor.
That began to change by the mid-1960s, as HDB shifted towards larger flats with self-contained kitchens and bathrooms. The move to 2- and 3-room flat types gradually replaced the communal living arrangements of the early years with more private and comfortable homes, setting the template for the HDB flat as we know it today.
Unusual HDB facts you might not have known
From pre-war architectural quirks to modern design experiments, these unusual HDB facts prove that public housing is far from one-size-fits-all. While practicality and efficiency have shaped the majority of today’s flats, pockets of history and individuality are all across the island, often hidden in plain sight.
The next time you go house hunting, be sure to venture past the beaten path and find a place that best reflects your ideal lifestyle.
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Cover image adapted from: 8PROP, Darren Soh, Wikipedia, Google Maps
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