Overhead Allocation Guide for Specialty Trade Contractors |…

Overhead: Indirect costs of running your business that don't tie to a specific job. Examples: office rent, general insurance, admin staff wages, vehicle costs for non-job-specific vehicles.

Overhead Pool: The total of all overhead costs for a given period, typically calculated monthly or annually.

Overhead Rate: Overhead pool divided by a base (labor hours, direct costs, or revenue) to produce a rate that can be applied to individual jobs. Expressed as a dollar amount per hour or a percentage.

Direct Costs: Costs that can be directly tied to a specific job: direct labor, direct materials, subcontractors, and job-specific equipment. These are tracked at the job level and distinguished from overhead.

True Job Margin: The difference between a job's contract value and its total cost including both direct costs and allocated overhead. Represents the actual contribution to business profit, distinct from gross margin on direct costs only.

Why Your Job Margins May Be Wrong

If you cost a job by adding up labor, materials, subcontractors, and equipment — and then subtract that total from your contract value — you’re getting a gross margin number. Not a true job margin.

The gross margin ignores the cost of running your business. Your office rent, admin staff, general liability insurance, vehicle fleet, software tools, accountant’s fees — those costs exist regardless of which jobs are active. Every job your business runs needs to carry its proportional share of those costs.

When you ignore overhead in your job cost calculations, jobs appear more profitable than they actually are. You make business decisions based on job margins that don’t reflect what the job actually costs you. You bid new work at price points that may not cover your total costs, even if they appear to cover your direct costs.

The Bid That Looks Good But Isn’t

A specialty trade sub who bids a $200,000 job with $160,000 in estimated direct costs sees a 20% gross margin. That looks healthy.

But if their monthly overhead is $18,000 and their average monthly direct costs are $80,000, their overhead rate is 22.5%. The $160,000 job should carry $36,000 in overhead allocation. True estimated cost is $196,000, not $160,000. True estimated margin is 2%, not 20%.

That’s not an edge case. That’s a business running on thin margins without knowing it, because every bid uses direct cost margin as a proxy for true margin.

Choosing the Right Allocation Method

The direct cost percentage method is the most practical for most specialty trade subs. It’s simple to calculate, easy to build into estimates, and produces results that are consistent across jobs with similar cost structures.

The labor hours method makes more sense if your jobs vary significantly in labor intensity. A job that’s mostly materials and subcontracted work consumes less of your field supervision and project management overhead than a job that’s almost entirely self-performed labor. If that variation is significant in your job mix, a labor hours-based allocation is more accurate.

The revenue percentage method is the simplest but the least accurate. It assumes overhead consumption scales proportionally with job revenue, which isn’t true for jobs that vary in complexity, duration, or labor intensity.

Most owner-operators start with the revenue or direct cost percentage method because it’s easiest to implement and explains itself in a bid. As your business grows and your overhead structure becomes more complex, the labor hours method becomes more valuable.

How Often to Recalculate

Your overhead rate should match your current cost structure. If you hired two people in the last year, your overhead increased. If you moved to a smaller office, it decreased. An overhead rate calculated three years ago based on a different cost structure produces inaccurate job margins.

Annual recalculation, timed to your fiscal year close, keeps the rate current. Use actual overhead from the prior year and adjust for known changes in the coming year. Build the new rate into your estimate templates before the new year’s jobs start.

This is a 15-minute task once you know your numbers. The cost of not doing it is carrying the wrong margin expectations on every job you bid for the next 12 months.

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Q&A

How do specialty trade subcontractors allocate overhead to individual jobs?

The most common method is a direct cost percentage: calculate total monthly overhead divided by total monthly direct costs to get an overhead rate percentage. Apply that rate to each job's direct costs to determine the job's overhead allocation. The rate should be recalculated annually and built into your bid estimates.

Q&A

Why do subs who skip overhead allocation underprice their jobs?

If you bid based on direct costs and gross margin only, your margin target doesn't include the overhead the job needs to cover. A 10% direct margin target on a job with 12% overhead means the job actually runs at a negative contribution margin. Subs who consistently win work by appearing to have low prices but don't understand why they're...

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Frequently asked

Common questions before you try it

What is overhead allocation in construction job costing?

Overhead allocation assigns a portion of your indirect business costs (rent, insurance, admin staff, vehicles) to each job you run. Without overhead allocation, your job margin calculations only reflect direct costs and overstate the actual profit per job. A job that shows 12% gross margin after direct costs might show 3% or negative margin after absorbing its share of overhead.

What overhead costs should specialty trade subs include in their overhead pool?

Common overhead categories: office rent, general liability and umbrella insurance, non-job-specific vehicle costs, office and admin staff wages, equipment maintenance and depreciation for general-use tools, accounting and legal fees, software subscriptions, and any estimator time not directly billed to a job. Job-specific costs (dedicated equipment, job-site trailers, project management labor on a specific job) should be direct costs coded to that job, not overhead.

What is a typical overhead rate for a specialty trade subcontractor?

Overhead rates vary significantly based on business size and overhead structure. A small sub (2–5 employees, modest office costs) might have an overhead rate of 10–15% of direct costs. A larger sub with more office staff and fleet costs might run 20–30%. The important thing is calculating your actual overhead rate rather than using an industry average — your specific cost structure determines what rate you need to use in your bids.

What happens if I underprice my overhead rate?

If your overhead rate is too low, every job you bid is effectively covering less than its share of your overhead. You appear to make money on each job in direct margin terms but your total direct margins don't cover your total overhead. The business loses money even though jobs individually appear profitable. This is a common trap for subs who don't calculate an overhead rate at all and compete on direct cost margin only.

How does job costing software handle overhead allocation?

Most job costing platforms allow you to define an overhead rate that is applied to each job's direct costs automatically. When costs are entered against a job, the overhead allocation calculates and accumulates alongside the direct costs. This means your job cost report shows total job cost including overhead, giving you a true job margin rather than a gross margin that doesn't reflect business costs.

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Overhead Allocation Guide for Specialty Trade Contractors