Korean Apartment Sizes: 전용면적 vs 공급면적 Explained

The difference between exclusive use area (전용면적) and supply area (공급면적), pyeong conversion, and how to read Korean apartment listings accurately

If you have ever browsed Korean real estate listings, you have likely encountered a confusing array of size measurements: 평 (pyeong), 전용면적, 공급면적, 계약면적, and square meters all appearing side by side with different numbers for what seems to be the same space. Understanding exactly what each measurement includes — and what it excludes — is essential to comparing properties accurately and avoiding the common mistake of paying a higher price per unit area than you realize.

Pyeong (평): The Traditional Korean Unit

Pyeong is a traditional Korean and Japanese area unit still commonly used in casual real estate conversation despite being officially deprecated in Korean law since 2007. The conversion is:

1 pyeong = 3.3058 square meters = 35.583 square feet

Pyeong Converter

Pyeong To Sqm

So a "34평" apartment contains approximately 34 × 3.3058 = 112.4 square meters — but this is where the confusion starts, because 34평 almost certainly does not mean 112 square meters of actual living space. The 34평 figure typically refers to the 공급면적 (supply area), which includes shared spaces. The actual private living area may be only 84–85 square meters.

The Four Area Measurements You Will Encounter

1. 전용면적 (Jeonyong Myeonjeok) — Exclusive Private Area

This is the area within the walls of your unit that belongs exclusively to you: bedrooms, living room, kitchen, and bathrooms. It excludes everything outside your front door. This is the legally binding area for property tax calculations, LTV mortgage calculations, and subsidy eligibility.

Rule of thumb: When comparing apartments, always compare 전용면적, not the other measurements.

2. 주거공용면적 (Jugeo Gongyong Myeonjeok) — Residential Common Area

The shared spaces within your building's residential floors: corridors on your floor, stair landings, elevator waiting areas, and similar circulation spaces allocated proportionally to each unit.

공급면적 = 전용면적 + 주거공용면적

The 공급면적 is the figure most often used in marketing materials (분양 광고) because it produces a larger number that makes the apartment appear bigger than the competing exclusive-area figure.

3. 기타공용면적 (Gita Gongyong Myeonjeok) — Other Common Area

Building-wide common facilities: lobby, guard booth, gym, parking structure columns, mechanical rooms, and any other non-residential common area.

계약면적 = 전용면적 + 주거공용면적 + 기타공용면적

The 계약면적 (contract area) is the total floor space attributed to your unit for maintenance fee calculation purposes.

4. 서비스면적 (Service Area) — Bonus Unregistered Space

Balconies (베란다 or 발코니) and some terraces are not counted in the 전용면적 because they are legally classified as auxiliary spaces. This "free" space is a major selling point for Korean apartments — most buyers extend the balcony inward (확장 공사) to create additional living space that is not reflected in the official area figures.

Standard Apartment Sizes in Practice

Korean apartment listings conventionally describe units by their 공급면적 in pyeong, but the industry recognizes standard size categories by 전용면적:

Informal Name	전용면적	공급면적 (approx.)	Typical Pyeong Label
소형 (Small)	Under 59 m²	~21–24평	20평대
국민 평형 (Standard)	59 m²	~24–25평	24–25평
중형 (Mid)	84 m²	~33–35평	34평
대형 (Large)	114 m²	~44–46평	45평
초대형 (Extra-large)	135 m²+	50평+	50평대+

The "국민 평형" (national standard size) of 59 m² 전용 and the 84 m² 전용 are by far the most common sizes in the Korean market and the benchmarks against which pricing per square meter is typically evaluated.

Why the 84m² 전용 Unit Is Named "34평"

The arithmetic: 84 m² 전용 + approximately 26 m² of residential common area = 110 m² 공급면적 ÷ 3.3058 = 33.3 pyeong, rounded to 34평. So when a listing says "34평 아파트," it means 84 square meters of living space that you exclusively own, inside your walls — but the total floor space attributed to your unit for maintenance fees and building-wide calculations is closer to 130–140 square meters.

How to Calculate the True Price Per Square Meter

When comparing apartments, divide the price by the 전용면적 (not 공급 or 계약 area):

Apartment A: 600 million KRW, 34평 label, 84 m² 전용 → 7.14M KRW per 전용 m²
Apartment B: 590 million KRW, 33평 label, 82 m² 전용 → 7.20M KRW per 전용 m²

Apartment B is actually more expensive per square meter of actual living space, even though its advertised pyeong count and total price are both lower.