Re: ABOUT BUILDING LEVELS Hello, we go to Settings --> Floor General Settings tab. In idecad 7.022 version, the elevations are calculated according to the Ground Floor. Since your 3rd basement floor will be -350, it will be at 550 cm elevation. At first, the ground floor level and floor height should be adjusted, and then the floor height of an upper floor should be corrected. After the ground floor and upper floors are corrected, you can correct the elevations and floor heights of the basement floors. Attached is the file where I fixed the jeans.