Estimating General Conditions: A Complete Guide for Contractors

General conditions (GCs), often called jobsite overhead, are the costs of running a project that do not belong to any one trade: supervision, the field office, temporary facilities, cleanup, and the administrative work of getting a building built and closed out. Because they are spread across the whole job, they are easy to underestimate, and because many of them are tied to time, they grow every week a project runs long.

This post explains how to classify GC items, builds an example GC budget, and shows how the same budget supports a delay claim. For a condensed reference, see our general conditions guide.

General Conditions vs. General Requirements vs. Overhead

These terms get mixed up, so it helps to separate them:

• General requirements are the specification sections in CSI MasterFormat Division 01 (01 General Requirements). They describe administrative and temporary-facility obligations such as submittals, quality control, temporary facilities and closeout.
• General conditions is the cost category the estimator builds to satisfy those requirements and run the site. In AIA contracts, “General Conditions” is also the name of the contract document (A201), which is a different thing again.
• Home office overhead covers the company’s costs that are not tied to one project: office rent, executives, accounting, estimating staff. It is usually carried as a separate markup, not in GCs.

Keep home office overhead out of the GC estimate. Mixing the two makes it hard to defend either number in a change order or claim.

Three Ways GC Items Behave

The most useful way to estimate GCs is by cost driver.

Driver	How to price	Typical items
Time-based	Monthly (or weekly) rate x duration	Superintendent, project manager, project engineer, field office rental, temporary power usage, toilets, vehicles, internet
Fixed / lump sum	One-time cost regardless of duration	Trailer delivery and removal, project sign, temporary fence installation, final cleaning, as-builts and O&M manuals
Quantity-based	Quantity x unit rate	Dumpster pulls, testing (per cylinder set or per inspection visit), temporary protection per SF, final clean per SF

Some items straddle categories. Dumpster service, for example, depends on how much demolition and packaging waste the trades generate, not just the calendar. Bonds and builder’s risk insurance are usually priced as a percentage of contract value and are often carried below the line with markups rather than in GCs; decide which your company does and be consistent.

Worked Example: A 10-Month GC Budget

Example: a 60,000 SF, 10-month commercial interior and core project with an estimated direct cost of $6,200,000. All rates are illustrative 2026 figures and include labor burden where applicable. Use your own payroll costs and local vendor quotes.

Time-based items

Item	Monthly rate	Months	Cost
Project manager (50% allocated: $14,000 x 0.5)	$7,000	10	$70,000
Superintendent (full-time, includes closeout)	$16,500	10.5	$173,250
Project engineer	$9,500	9	$85,500
Field office trailer rental	$950	10	$9,500
Temporary toilets (3 units x $175)	$525	10	$5,250
Temporary power usage	$1,200	10	$12,000
Superintendent vehicle	$1,100	10	$11,000
Time-based subtotal			$366,500

Arithmetic check: $70,000 + $173,250 + $85,500 + $9,500 + $5,250 + $12,000 + $11,000 = $366,500.

The superintendent runs half a month past substantial completion for punch list and closeout; the project engineer starts after mobilization, so both carry durations different from the 10-month schedule.

Fixed and quantity-based items

Item	Basis	Cost
Dumpster pulls	6 pulls/month x $550 x 10 months	$33,000
Trailer delivery, setup and removal	Lump sum	$2,400
Temporary fence	1,400 LF x $4.50/LF	$6,300
Final cleaning	60,000 SF x $0.35/SF	$21,000
Project sign	Lump sum	$1,500
Closeout documents and as-builts	Lump sum	$3,000
Subtotal		$67,200

Arithmetic check: $33,000 + $2,400 + $6,300 + $21,000 + $1,500 + $3,000 = $67,200.

Total and percentage

• Total GCs = $366,500 + $67,200 = $433,700
• GCs as a percentage of direct cost = $433,700 / $6,200,000 = 7.0%

A percentage is a useful sanity check against your own past jobs, but it should be the result of the build-up, not the starting point. A short, dense project and a long, slow one with the same direct cost can have very different GC percentages.

What a delay costs

The monthly run rate of the time-based items at full staffing is:

$7,000 + $16,500 + $9,500 + $950 + $525 + $1,200 + $1,100 = $36,775/month

If the schedule extends two months for reasons outside the contractor’s control, the extended general conditions are $36,775 x 2 = $73,550, before any markup allowed by the contract. This is why a time-based GC schedule, priced by month, is far easier to use in a change order than a single lump-sum GC line. Our change order pricing guide covers how to present that cost.

What Else Belongs in GCs

Check the Division 01 sections and the contract for items such as:

• Survey and layout, if not carried by a trade
• Temporary heat, enclosure and weather protection
• Safety program costs: site-specific safety plan, first aid, fall protection not provided by subs
• Hoisting or shared equipment, such as a forklift or telehandler used by several trades
• Testing and special inspections the contractor is required to pay for
• Scheduling software, document control and project photography
• Winter conditions, dewatering or traffic control where not in a trade scope
• Permits and fees, if the contract assigns them to the contractor

Checklist

• Schedule reviewed and a realistic duration used, including closeout
• Each staff position priced at burdened monthly cost with its own start and end dates
• Items classified as time-based, fixed or quantity-based
• Division 01 sections read line by line and compared to the GC list
• Items carried by subcontractors excluded from GCs (and confirmed during bid leveling)
• Home office overhead, bonds and insurance handled consistently outside or inside GCs
• Monthly run rate calculated for use in delay and change pricing
• GC percentage compared to similar past projects as a final check

Common Mistakes

• Using a flat percentage instead of a time-based build-up.
• Pricing the schedule the owner wants rather than the one the work requires.
• Leaving out closeout time. Supervision and the trailer do not stop at substantial completion.
• Double carrying items such as dumpsters, hoisting or temporary protection that subs already include.
• Forgetting burden on field staff salaries. See our labor burden post.
• Missing Division 01 requirements like mock-ups, commissioning support or extended warranty administration.

How F&K Estimatings Can Help

Our estimates carry general conditions as an itemized, time-based schedule tied to the project duration you give us, so the numbers can be adjusted or reused if the schedule changes. This is part of our construction estimating services. See pricing for a quote on your next bid.