What is fire sprinklerin construction?

It depends on hazard classification and head type. Under NFPA 13, a standard spray head in a light hazard occupancy may protect up to 225 sf, and ordinary hazard tightens that to 130 sf, so plan roughly one head per 130 to 225 sf of floor area. Walls, soffits, and obstructions push the practical coverage below the code maximum, which is why head counts from real layouts run higher than a simple area division suggests.

Because the final layout depends on hydraulic calculations against the actual water supply, and on coordination with ductwork, structure, and ceilings that are not settled at bid time. Contract documents typically give performance criteria (hazard classes, water flow test data, riser locations) and the licensed fire protection contractor engineers the system in shop drawings reviewed by the engineer and the fire marshal. The GC estimator prices it as a sub quote and verifies the assumptions behind each bid.

Hazard class sets the design density, the gallons per minute each square foot of the remote area must receive, and the maximum coverage per head. Light hazard offices need less water than ordinary hazard warehouses or manufacturing space, which means smaller pipe, fewer heads per area, and a lower cost per square foot. Misclassifying a space, like treating dense storage as light hazard, produces a bid-day price that cannot survive the fire marshal's review.