Long-Lead Item
Materials or equipment that must be ordered early to arrive on time.
Quick Answer
A long-lead item is a material or piece of equipment whose time from order to delivery is long enough that it must be ordered well in advance to avoid delaying construction. Lead time includes submittals, approvals, fabrication, and shipping. Common examples are switchgear, generators, elevators, structural steel, and custom glazing.
The Full Picture
Construction schedules assume materials arrive when crews need them. For most items that is easy, but engineered and custom products are built to order, and their total lead time can run many months. When that duration is longer than the gap between contract award and installation, the item becomes a schedule risk and has to be managed separately.
Mechanically, lead time is more than manufacturing. It starts with submittal preparation, then design team review and possibly resubmittal, then release for fabrication, production, and shipping. A piece of equipment with a short factory time can still be long-lead if its shop drawings need several review cycles. A procurement log tracks each item's required on-site date and works backward to the latest date it must be released.
In practice, lead times shift with the market. Electrical gear such as transformers and switchgear has at times seen very long lead times due to supply constraints, and GCs confirm current lead times with suppliers rather than relying on old assumptions. The preconstruction team flags these items at early design reviews and tracks them through procurement.
For preconstruction, the failure mode is discovering a long-lead item after the schedule is set. Good practice identifies candidates from the drawings and specs at each design milestone, confirms lead times with suppliers, builds them into the schedule and submittal register, and recommends early procurement when the math does not work.
Real Examples
Common Misconceptions
People assume: Lead time is just the manufacturer's production time.
Actually: It includes submittal preparation, review and resubmittal cycles, fabrication release, production, and shipping. Slow submittal reviews can turn an ordinary item into a long-lead item.
People assume: Long-lead items are the same on every project.
Actually: Lead times change with market conditions, specifications, and suppliers. An item that shipped quickly two years ago may now take far longer, so lead times should be confirmed with suppliers for each project.
Frequently Asked Questions
What are common long-lead items in construction?
Electrical switchgear, transformers, and generators; chillers, boilers, and air handlers; elevators and escalators; structural steel; custom curtain wall and glazing; and specialty equipment for labs, kitchens, or medical spaces.
How do you identify long-lead items?
Review drawings and specifications at each design milestone for engineered or custom products, confirm current lead times with suppliers, and compare them against the schedule's required on-site dates.
How do long-lead items affect the schedule?
If an item cannot be delivered by its required date, the activities that depend on it are delayed, which can push the critical path. That is why long-lead items are tracked in a procurement log tied to the schedule.
What is the relationship between long-lead items and early procurement?
Early procurement is the main response to long-lead items: purchasing or releasing them before the full design or main bid is complete so they arrive in time.