under construction; being built
Refers to a building or structure that is currently in the process of being constructed. Often used in real estate or construction contexts.
This building is still under construction.
I toured a house that is under construction.
Compound of 建て (tate, 'building') + 掛け (kake, 'in the process of'). The exact historical derivation is uncertain, but the meaning is transparent from its components.