Job costing and overhead accounting

Every dollar a contractor spends is either charged to a job or carried as overhead. Where that line is drawn, and how shared costs are spread across jobs, decides each job's reported margin, the firm's apparent overhead rate, the markups used in bids and the volume of work the firm needs just to break even. This lesson looks at job costing from the company's side: what belongs in job cost, how labor burden and shared costs reach jobs through clearing accounts and allocation rates, what happens when allocation rates are wrong, and how overhead and gross margin together determine break-even volume. CON-300 covered how overhead and burden are priced in a bid; here the question is how they are accounted for once the money is spent.

Direct costs, indirect costs and overhead

Contractors usually divide costs into three groups. Direct job costs are incurred for a specific job and can be traced to it: labor on the job, materials installed, subcontracts, equipment working on the job, permits. Indirect job costs, often called field overhead or general conditions, support a job but are not part of the permanent work: site supervision, site offices, temporary utilities, safety, cleanup. Most contractors charge these to the job too. Home office overhead, or general and administrative expense, supports the business as a whole and is not charged to jobs: the head office, executives, estimating, accounting and marketing.

Two contractors with identical economics can report very different gross margins if one charges its project managers to jobs and the other carries them in overhead. Neither choice is wrong, but each firm should be consistent, should price its bids on the same basis it accounts for costs, and should be careful when comparing its margins with industry surveys. Surety analysts usually ask how project management and equipment are treated before comparing a firm's ratios with benchmarks.

Labor burden and the payroll clearing account

A worker's wage is only part of the cost of employing them. Employers also pay Social Security and Medicare taxes under FICA, federal and state unemployment taxes (FUTA and SUTA), workers' compensation premiums and, often, paid leave and health benefits; for union trades, fringe benefit contributions to union trust funds. CON-300 showed how these are built into a loaded labor rate for estimating. In the accounts, most contractors handle them through a payroll burden clearing account.

The method works like this. Each week, jobs are charged the gross wages from timecards plus a burden at a standard percentage. The actual burden costs, such as remittances and premiums, are posted to the clearing account as they are paid. If the standard rate is right, the amounts charged out to jobs and the actual costs posted in will roughly cancel, and the clearing account will hover near zero. If not, the balance shows burden that has been under-absorbed (charged to jobs too little) or over-absorbed (charged too much).

# Burden clearing for one quarter (illustrative)
wages_charged_to_jobs = 1_960_000
standard_rate = 0.32                      # burden charged as 32 % of wages
burden_charged = wages_charged_to_jobs * standard_rate
actual_burden = {"payroll taxes and premiums": 268_000,
                 "workers compensation": 121_000,
                 "vacation and holiday pay": 158_000,
                 "benefits and union contributions": 132_000}
actual = sum(actual_burden.values())
balance = actual - burden_charged
print(f"Burden charged to jobs: {burden_charged:,.0f}")
print(f"Actual burden incurred: {actual:,.0f}")
print(f"Under-absorbed burden:  {balance:,.0f}  "
      f"(actual rate {actual / wages_charged_to_jobs:.1%})")

Burden charged to jobs: 627,200
Actual burden incurred: 679,000
Under-absorbed burden:  51,800  (actual rate 34.6%)

Here the actual burden is 34.6 % of wages, not 32 %. Jobs have been under-charged $52,000 for the quarter, so their reported margins are slightly too high and the $52,000 sits in the clearing account. At year-end, or quarterly, the balance must be dealt with: either allocated to the jobs that used the labor, in proportion to wages, or written off to overhead. Leaving it unexamined distorts both job margins and overhead. A persistent under-absorption also means the bid rates in CON-300 are too low.

Indirect cost pools and allocation

Some costs serve many jobs but cannot easily be traced to one: a fabrication shop, a yard and warehouse, small tools, a safety department, a fleet of pickup trucks. Contractors collect these in indirect cost pools and allocate them to jobs with a rate based on a measure of use, such as labor hours, labor dollars, equipment hours or direct cost. The rate is set at the start of the year from budgets and adjusted when actual costs or volumes differ.

A good allocation base is one that drives the cost. Small tools wear out in proportion to hours worked, so labor hours are a reasonable base; yard handling is driven by material deliveries. Allocating everything by revenue or direct cost is simple but can distort job margins, charging a heavily subcontracted job for shop and yard costs it barely uses.

General and administrative overhead and its recovery

Home office overhead is not charged to jobs, but it must be recovered through job gross profit. Lesson 3 showed Kestrel's overhead of $3,300,000, or 5.7 % of revenue. In a bid, the firm adds markups for overhead and profit (CON-300 Lesson 8). In the accounts, overhead is simply an expense of the period. Whether it is recovered depends on whether the firm's total gross profit for the year exceeds its overhead, which in turn depends on volume and margins.

Overhead is largely fixed in the short run. Office salaries, rent and software subscriptions do not fall when the firm wins less work. That makes a contractor's profit very sensitive to volume: in a busy year overhead is spread over more work and margins look healthy; in a slow year the same overhead consumes most of the gross profit.

Break-even volume

The break-even volume is the revenue at which gross profit just covers overhead. If gross margin is roughly constant as a percentage of revenue and overhead is fixed, the calculation is simple.

overhead = 3_300_000
for gm in (0.065, 0.075, 0.085, 0.095):
    breakeven = overhead / gm
    print(f"Gross margin {gm:.1%}: break-even revenue {breakeven / 1e6:5.1f}M")
# Profit at different volumes with 8.5 % margin
for revenue in (35e6, 45e6, 58.4e6, 70e6):
    op = revenue * 0.085 - overhead
    print(f"Revenue {revenue / 1e6:5.1f}M: operating income {op:>11,.0f}")

Gross margin 6.5%: break-even revenue  50.8M
Gross margin 7.5%: break-even revenue  44.0M
Gross margin 8.5%: break-even revenue  38.8M
Gross margin 9.5%: break-even revenue  34.7M
Revenue  35.0M: operating income    -325,000
Revenue  45.0M: operating income     525,000
Revenue  58.4M: operating income   1,664,000
Revenue  70.0M: operating income   2,650,000

At an 8.5 % gross margin, Kestrel needs about $38.8 million of revenue to cover its overhead. Each million dollars of revenue above that adds about $85,000 of operating income; each million below costs $85,000. If its average margin slipped to 6.5 %, the break-even rises above $50 million, which is close to its current volume. Break-even analysis is a powerful planning tool because it shows management how much work it must win, at what margin, to stay profitable, and how much overhead the firm can afford.

In practice, overhead is not perfectly fixed. A firm that grows from $40 million to $70 million will add estimators, project managers and office staff, so overhead steps up in increments. The break-even calculation is best done for a planned range of volume with the overhead budget that goes with it, a topic Lesson 12 returns to.

Under-recovery when volume falls

When volume drops below plan, the overhead percentage used in bids is no longer enough. CON-300 Lesson 8 showed the pricing side: the firm must either raise markups, which may lose bids, cut overhead, or accept lower profit. The accounting side is that the firm's reported gross profit, however good each job's margin, will not cover overhead.

Job profitability and company profitability

Because overhead is recovered in total, not job by job, a job with a positive gross profit is contributing to overhead even if its margin is below the bid markup. In a slow market, contractors sometimes accept work at a margin that covers direct and indirect job costs but not a full share of overhead, reasoning that some contribution is better than none. That can be sensible in the short term, but if the whole backlog is priced that way, the firm will lose money year after year. The WIP schedule and the overhead budget together show whether the firm's total expected gross profit covers its overhead; a firm that tracks only job margins may not notice that its total is falling short.

Cost behavior and activity-based thinking

Some contractors analyze overhead by activity to understand what drives it. Estimating cost is driven by the number of bids, not the revenue won; accounting cost by the number of transactions and jobs; project management cost by the number and complexity of jobs. A firm that bids many small jobs may carry heavy estimating and administration costs relative to revenue. Understanding these drivers helps management decide which markets are worth pursuing and set overhead allocations for pricing that reflect the true cost of each type of work, even if the financial statements continue to treat overhead as a period expense.