Which floor do “LG1” and “LG2” refer to in a building? What does LG mean here?

The LG1 floor is the abbreviation of Low Ground floor 1 (one floor below the ground), which is minus 1 floor, and the LG2 floor is the abbreviation of low ground floor 2 (two floors below the ground), which is minus 2 building. LG: stands for Lower Ground, indicating the underground floor.

L stands for Level, which also means the number of layers, such as 1L 2L 3L 4L, which is also very common.

There is another difference to note here. Most countries use "ordinal + floor" to express the number of floors on the ground, but countries such as the United Kingdom, Australia, and New Zealand that speak British English have some differences. In these countries, the first floor is not the "first floor" but the "ground floor".

The LG+ number is the LG+ number we sometimes see, and is more commonly used in the UK. P is the abbreviation of Park. P plus a number indicates an underground parking lot, which is generally used in hotels or guesthouses. Similar to B plus a number, it indicates the number of underground floors.

Sometimes we still see M, but there are different opinions on the meaning of this letter. One theory is that foreigners think the number 13 is unlucky, and M is the 13th number in the alphabet, so M is used to refer to the 13th floor. It is also said that M stands for Mezzanine, which means mezzanine.

F means Floor, which means the number of layers, such as 1F 2F 3F 4F, which is very simple and clear. Note: Some building signs have both lg1 and lg2 as well as b1 and b2. For example, the picture below is Shanghai iapm, where lg refers to the underground shopping mall and b refers to the underground parking lot.