Does anyone know what hashtag could I use to describe a building for startup incubator?
Tag, not “hashtag”. It has no hash symbol.
Most numerous are some dozens of office=incubator
. However, it mixes incubator:business_incubator=yes
and incubator:business_accelerator=yes
.
Single-digit instances of office=startup_incubator
and office=business_incubator
are more specific.