specialist subcontract work
Used in the construction industry to refer to work contracted out to specialized trades (e.g., electrical, plumbing, scaffolding) rather than performed by the main contractor.
On this site, the electrical work is subcontracted as specialist trade work.
Please get estimates for the specialist subcontract work from each trade contractor.
下請け is a general term for subcontracting, while 職別工事 specifically refers to work divided by trade specialty in construction.
専門工事 is a broader term for specialized construction work, not necessarily implying subcontracting by trade.
Compound of 職別 (trade-specific, occupational) and 工事 (construction work). The exact historical derivation is uncertain, but the term is conventionally used in the Japanese construction industry.