the start/commencement of construction work; beginning of building operations.
新しい橋の着工式が市役所の前で行われた。
The groundbreaking ceremony for the new bridge was held in front of city hall.
天候不良のため工期が延び、着工は来月にずれ込んだ。
Due to bad weather the schedule was delayed, and construction will start next month.
着工前に近隣住民への説明会を開く必要がある。
A briefing for nearby residents needs to be held before construction starts.