Two erectors can look at the same tonnage of steel and price it very differently, because erection is not a materials cost. It is field labor and equipment, and it is shaped by how hard the steel is to reach, stage, and connect on your specific site. Here is what actually moves the number, so you can read erection bids on scope instead of on the bottom line. As with any real estimate, this page explains the drivers rather than quoting prices, because the number depends on your site, drawings, and schedule.
Why erection is not priced by the ton
Weight matters, but it is a weak predictor of erection cost on its own. The same frame is cheap to stand on an open site with room to lay down steel and swing a crane, and expensive on a tight urban lot with restricted access, live traffic, and no staging room. Erection cost tracks the difficulty of the field operation, not just the pounds of steel. That is why an erection bid should be read through the lens of site conditions and sequence.
The six drivers of erection cost
Field cost is the sum of these drivers, and any one of them can separate two bids on identical tonnage.
| Driver | What it affects | Why it moves the number |
|---|---|---|
| Crane and rigging | Equipment and pick cycle | Crane size, reach, and moves are a large share of cost |
| Site access and laydown | Crew efficiency | Tight access and no staging slow every pick |
| Sequencing | Schedule and rework | Out-of-order steel means restarts and idle time |
| Connection type | Field labor hours | Field welding and moment connections take longer than bolting |
| Schedule pressure | Overtime and crews | Compressed timelines add shifts and premium labor |
| Safety requirements | Setup and time | Fall protection, exclusion zones, and rigging plans take time to do right |
Crane, rigging, and site access: the biggest levers
The largest driver is usually crane and rigging, and it is inseparable from site access. Crane size, where it can sit, how far it has to reach, and how many times it must be repositioned all drive cost, and a constrained site amplifies every one of those factors. When access is tight, laydown is limited, or the crew is working around live traffic or an occupied adjacent building, the pick-and-set cycle slows and the hours climb. Share your site logistics early, because they move the erection number more than almost anything else.
Sequencing and connection type
Sequencing is where an efficient erection either flows or stalls. When steel arrives and is erected in the planned order, the crane and crew keep a rhythm. When members show up out of order, the crew waits, re-rigs, or restarts, and every stall is paid labor. This is one reason the single-source model helps on cost: fabrication is sequenced to the erection plan, so steel lands in the order the field needs it.
Connection type sets the field labor per joint. Bolted connections are the fastest to make in the field. Field welding and moment connections take more time, more inspection, and often more equipment, which raises the hours per member. The connection design is set upstream by the engineer, but it flows straight into the erection cost.
Schedule and safety
Schedule pressure and safety both carry cost that belongs in the estimate. A compressed timeline can require additional crews, extra shifts, or overtime, all at premium rates. Safety is not a line to trim: fall protection, exclusion zones, rigging plans, and a documented program take time to execute properly, and that time is real. A qualified erector prices safety in rather than pretending it is free, which is one more reason to vet the sub on more than price. See how to choose an AISC-certified steel erector for the full vet.
How a real erection quote is built
An estimator builds an erection number from crew size and duration, crane and equipment, rigging, mobilization, and the site-specific factors above, then adjusts for sequence and schedule. Give them complete information, site logistics, the erection sequence, connection details, and the real timeline, and they carry less contingency for the unknowns, which tightens the bid. For the shop half of the steel budget, pair this with what drives structural steel fabrication cost.
TMG | Tri-State Metal Group self-performs erection with its own crews across SC, NC, and GA and prices the field work against a real erection plan, not a blanket rate. Send us the drawings and site logistics and we will build an erection number you can compare on scope.