HDB flats with balconies are already a rare find, and even among those, no two are quite alike. Newer builds tend to face outward, while older resale units usually come with internal balconies tucked within the unit’s own footprint.
Most of us think of a balcony as a spot for drying clothes or catching some fresh air after a long day. But there’s an even rarer type that most people have never come across. Some older HDB designs had a feature called interaction balconies, which face the interior of the block rather than its facade.
Here’s what we know about this unique HDB feature, and where you might spot one.
HDB’s “Interaction” balconies within the atrium
Image adapted from: HDB
Rather than facing outward, these balconies look inward over a shared atrium with a high ceiling, with multiple units all peering into the same open space. HDB officially calls them “balconies within an atrium” in its renovation guidelines.
Technically, the balconies are open to the air above, with only the ceiling of the unit above them overhead, giving a sense of openness while still being enclosed within the block.
Floor plan of a 4-room HDB with an interaction balcony.
Image credit: PropertyGuru
This creates a unique environment where homeowners can enjoy the perks of a balcony without the usual headaches. Natural light and airflow are still present, but without any frantic dashes to rescue your laundry or risk having your balcony furniture bleached by the harsh afternoon sun, making the space genuinely usable all year round.
Trade-offs of interaction balconies
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The biggest trade-off is privacy. Neighbours across and above can see directly into your space, and sound travels easily through the shared atrium. Music, conversations, or even the occasional heated argument can all drift to nearby units, so residents do need to be mindful.
Some TikTok users have joked that the layout resembles a prison complex, or dubbed it an oxymoronic “indoors open-air balcony.” You step outside into fresh air and sunlight, yet remain very much inside the block, which could be charming to some, while it might feel a little uncanny to others.
Natural balcony lighting can also be inconsistent, even within the same block. Depending on the atrium’s depth and width, higher-floor units may spend parts of the day in shadow, while lower floors pick up more reflected light from opposite walls.
Where can you find HDB blocks with interaction balconies?
Image credit: PropertyGuru
While there isn’t an official public list, online discussions have flagged a few blocks where you can spot them in the wild.
Some examples include Jurong West Street 91 Block 950, Pasir Ris Block 469, and blocks at Bukit Batok West Avenue 6, which were all built in the late 1980s or early 1990s.
HDB interaction balconies
Interaction balconies are one of the unique floor plans that make older HDB flats stand out. They offer a rare mix of indoor comfort and outdoor air, giving residents a space that’s both practical and breezy.
For homeowners or anyone who enjoys spotting unusual HDB features, interaction balconies are proof that there are still surprises hiding in plain sight across our familiar housing blocks.
For more unusual HDB facts:
- 20 unusual HDB facts that are hidden in plain sight
- Did you know there’s an “HDB estate” on Christmas Island?
- Did you know Bukit Purmei’s HDB flats overlook a royal burial ground?
Cover image adapted from: PropertyGuru
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