Number of storeys below ground [HB] - jcgomezz/Building_taxonomy GitHub Wiki

Number of storeys below ground unknown [HB99]

Range of number of storeys below ground [HBBET]. Example: Range (meters) HBBET: 3,1 (between 1 and 3 levels of basement)

Exact number of storeys below ground [HBEX]. Example: Fixed number (integer) e.g. HBEX:2 (two levels of basement)

Approximate number of storeys below ground [HBAPP]