You take your shoes off in your Seoul room, step onto the floor and find it warm. That isn’t a quirk of your building. Korea has heated its rooms from the floor up for a very long time, and the habit shapes how people sit, sleep and walk indoors.[1]
Below, we explain how ondol works, then cover the three places a visitor is most likely to meet it: the heating panel in your room, the old system at Gyeongbokgung Palace, and the moment at the door when shoes come off. We read the government’s own pages on ondol and on palace visiting hours on October 9, 2026 (how we research).
Ondol heats the floor, and the floor heats the room
Ondol is underfloor heating. In the traditional version, a fire is lit in a firebox called an agungi, usually in the kitchen. The heat passes over a low ridge into channels under the room, called gorae, warms the flat stones laid over them, called gudeuljang, and leaves through a flue and a chimney.[2] The ridge spreads the heat evenly and stops ash from drifting into the channels, and a deeper pit at the far end catches ash and slows the smoke.[2]
The warm stones then heat the room in three ways at once, according to the Korea Heritage Service: by conduction through the floor you touch, by radiation from the floor, and by convection as warm air rises and circulates.[2] Korea.net puts the difference with Western heating simply. A fireplace or radiator heats the space around it, while underfloor heating warms the floor first, then the warm air rises and heats the whole room.[1]
The same Korea Heritage Service article, written by a professor of hanok architecture, also compares the three ways modern buildings are heated. Forced-air heating through ducts is the cheapest but the least comfortable. Hot-water heating, used in most Korean households, costs more than forced air but is fairly comfortable. Radiant heating of the ondol kind is the least economical of the three, and the article calls it the most comfortable and eco-friendly.[2] In short, the floor is the heater, and that design choice runs through the rest of this guide.
A very old idea in a modern pipe
Korea.net says underfloor heating on the Korean Peninsula is estimated to be more than 2,000 years old, based on brick and stone ondol remains dated to between the 200s B.C. and 0 B.C. found in several parts of the peninsula.[1] The Korea Heritage Service describes early versions that heated only part of a room, and says the full-floor system is generally thought to have been completed in the late Goryeo period.[2] The word “ondol” itself is generally thought to have settled into use from the 19th century on, after a run of other names, including gudeul.[2]
The idea survived the move to apartments. Korea.net notes that the system has changed only a little, with insulated pipes taking the place of the old stone slabs.[1] The Korea Heritage Service says most Korean households now use hot-water heating, which supplies the room with water heated by fire or electricity.[2] Ondol culture was designated national intangible heritage on April 30, 2018.[2]
The heating panel in your room
Your room’s floor heating has a control of its own, and it differs by maker and model. We looked for a manufacturer’s own manual to confirm button names and warm-up times, but couldn’t open one to check, so we won’t guess at them here.
What we can suggest:
- Ask your host on arrival which button turns the floor heating on and off, and which setting gives hot water only. Hosts know their own panel.
- Look for a printed manual near the panel or in the house guide.
- Ask how long the floor usually takes to warm up, so you don’t keep turning the setting higher while you wait.
- Before you go out for the day, check with your host whether to turn the heating down or leave it as it is.
Where you can see the old system: Gyeongbokgung Palace
If you want to see where the heat used to come from, Gyeongbokgung, in central Seoul, is a good place to start. Korea.net’s article on ondol shows two scenes there: Jibgyeongdang, which it describes as a Joseon queen’s chamber with a traditional underfloor heating system, and an agungi firebox at the palace.[1]
The palace’s ondol also left marks above ground. The Korea Heritage Service notes that the Amisan chimney at Gyeongbokgung, designated a Treasure, let out the smoke that had passed under the ondol rooms of Gyotaejeon, the queen’s living quarters.[2] It’s a reminder that the smoke, and the heat with it, traveled under the floor before it left.
We haven’t confirmed whether any firebox or room interior is open for a closer look, so plan to see these from the outside. Opening times matter more in winter. The palace is closed on Tuesdays. If a Tuesday is a public holiday, the palace is open that day and the weekly closing moves to the next day that isn’t a public holiday.[3] From November to February it’s open from 9 a.m. to 5 p.m., with last entry at 4 p.m.[3]
So where do shoes come off?
The warm floor also explains what happens at the front door. Korea.net makes the chain of cause and effect explicit: since the floor was warm, people sat on the floor; where people sit on the floor, they also eat and sleep there; and so wearing shoes in the house is generally frowned upon.[1]
| Place | Shoes? | Source |
|---|---|---|
| Inside a Korean home | Off. Wearing shoes in the house is generally frowned upon | [1] |
| Floor-seating restaurants, hanok stays | Not covered here: we found no official page to cite | — |
We kept this table to what an official source supports, and we’d rather leave a row open than guess. If you’re unsure, watch what others do at the edge of the raised floor, or ask the staff before you step up.
Public bathhouses and jjimjilbang have their own rules about where shoes and clothes go, and we’re covering those in a separate guide.
Good to know
- Bring socks you’re happy to be seen in. In a home, you’ll be in them all evening.
- On arrival, ask your host how to switch the floor heating on and off, and how long it takes to warm up.
- Planning Gyeongbokgung in winter? Avoid Tuesdays and arrive before 4 p.m.[3]
- Indoor spaces with heated floors can feel warm when it’s freezing outside, so dress in layers you can take off. Our Seoul winter guide covers what to pack.
Palace hours were checked on the Royal Palaces and Tombs Center’s page on October 9, 2026. Hours can change, so check again before you go.
The floor is one reason daily life in Seoul works the way it does. Another is how the city handles road crossings, explained in jaywalking in Seoul. More everyday guides are in Seoul, every day.
