What is the elevation of the basement of the building?
Elevation represents the vertical height of a part of a building relative to the datum, that is, the elevation zero point, which is the basis for vertical positioning.
The elevation of the basement refers to how many meters the bottom of the building foundation is below 0.000 relative to the building.
Absolute elevation refers to the elevation with the datum plane uniformly specified by a country or region as zero point. China stipulates that the average sea level of the Yellow Sea near Qingdao is zero, and the calculated elevation is called absolute elevation.
Relative elevation means that the height of the main ground on the first floor of a building is zero as the starting point of elevation, and the calculated elevation is called relative elevation.