Korean Apartment Floor Area: Why 84㎡ Is Called 34 Pyeong

An apartment with 84㎡ of jeonyong myeonjeok (exclusive-use area) is called 34 pyeong because Korean size labels are based on supply area of roughly 112㎡, not on the private space itself. Convert 84㎡ alone and you get 25.4 pyeong. The 28㎡ or so in between is shared residential area — lifts, corridors and stairwells.

The same figure of 84 also describes two completely different homes depending on whether it appears on an apartment or an officetel listing. Apartments quote supply area as the sale area; officetels quote contract area, and even the governing statute differs. When the basis differs, the price per square metre is not a figure measured with the same ruler.

What each of the four area terms covers

The names look similar but the scope stacks in layers. KB Think defines exclusive-use area as "the space actually needed for living, excluding the balcony" — the living room, kitchen, bedrooms and bathrooms inside your front door. Add the shared residential area used by everyone in the building (lifts, stairs, corridors) and you get supply area. Add other common area on top — parking, the security office, the management office, the seniors' room — and you get contract area.

One thing sits outside all of it: the balcony. As IBK explains, the balcony is classified as service area and appears in none of the three totals. Yet once it is enclosed, it becomes floor you actually walk on. It is the item that no area figure captures but that changes perceived space the most.

• Exclusive-use area = your home inside the front door (balcony excluded)
• Supply area = exclusive-use + shared residential (corridor, stairs, lift)
• Contract area = supply area + other common (parking, security, community)
• Service area = balcony (in none of the totals)

Why 84㎡ is 34 pyeong, not 25

One pyeong equals 3.3058㎡. Divide 84㎡ by that and you get 25.41 pyeong, yet the market label is 34 pyeong. The two differ because they rest on different bases. The 34-pyeong label is supply area, and 34 × 3.3058 = 112.4㎡ is what it actually denotes. The 28.4㎡ gap against 84㎡ is this unit's share of common residential space.

The phrase "34 pyeong" points at two different homes: the supply area of an 84㎡ unit is 34 pyeong, and 114㎡ of exclusive-use area is itself 34.5 pyeong.

Exclusive-use ratios worked backwards from the labels

Invert the correspondence KB gives between exclusive-use area and the conventional pyeong labels and the ratio falls out. Supply area is reconstructed as label × 3.3058, then exclusive-use area is divided by it.

Notice that the shared residential area clusters between 23.6㎡ and 28.4㎡. Corridors, stairs and lifts do not shrink in proportion when the unit does. Because they behave like a fixed cost, smaller units carry lower exclusive-use ratios — 71.4% at 59㎡ against 80.2% at 114㎡. That is why small units in the same complex feel tight relative to their stated pyeong: structure, not taste.

These figures come from reverse-engineering conventional labels, so they shift by complex. Corridor-access versus stairwell-access layouts, tower versus slab designs, and the number of lifts all move the real ratio by several percentage points. For an exact number, divide the exclusive-use and supply areas printed in the offering notice or the property register.

Why an officetel of the same 84㎡ is smaller

According to Asia Economy, apartment sale areas fall under the Housing Act while officetels fall under the Building Act. Apartments quote supply area; officetels quote contract area, which folds in other common space as well. Exclusive-use ratios run 70–80% for apartments but around 50% for officetels. Combine that with the near-absence of balconies and the industry treats a 59㎡ apartment with an enclosed balcony as comparable in usable space to an 84㎡ officetel, the same report notes.

Assuming a total price of 600 million won, here is how that difference lands in the headline price per square metre. Exclusive-use ratios of 74.7% and 50.0% are applied, and the enclosed balcony range of 25–40㎡ comes from the same report.

On the quoted basis the officetel looks 33% cheaper — 3.57 million won per square metre against 5.34 million. Divide by the floor you actually use and the order reverses: 7.14 million for the officetel, 4.84–5.50 million for the apartment. The same total price points in opposite directions purely because the denominator differs, not because one is cheaper.

The measurement method also splits at 30 April 2015. Per the same report, officetels permitted before that date measure exclusive-use area to the centreline of the wall, while later permits and apartments measure to the inner wall face. An older officetel can therefore be genuinely smaller at the same stated 84㎡. Whether an officetel counts as a house for tax purposes is handled separately in the piece on how each tax applies its own test.

What to check

• Which basis the label uses — confirm whether "34 pyeong" in a listing means exclusive-use or supply area. Both 84㎡ and 114㎡ of exclusive-use area can be called 34.
• Compute the ratio yourself — exclusive-use ÷ supply area from the offering notice or register. It varies by several points between complexes at the same size.
• Enclosed balcony area — captured by no area figure yet the biggest swing in usable space. Ask about it separately.
• Officetels quote contract area — never compare the headline sale area directly with an apartment's. Convert to exclusive-use area first.
• Officetels permitted before 30 April 2015 — measured to the wall centreline, so the same label can mean less usable space. Check the approval date.
• Common area drives management fees — more shared space means higher monthly charges. The refundable portion at move-out is worked through for a 34-pyeong case in the long-term repair reserve calculation.

Sources

• Why is 84㎡ called 34 pyeong, not 25? — KB Think
• Same exclusive-use area, so why is an officetel smaller? — Asia Economy
• Exclusive, common, supply and contract area explained — IBK