What Are Overheads in Construction Estimating?
Overheads are the ongoing costs of running a construction business that exist regardless of which jobs are on the books — office or yard rent, admin wages, insurances, software subscriptions, vehicles and marketing are all typical examples. Because overheads cannot be tied to any single project, they are usually recovered by adding a percentage or margin across every job priced, rather than being itemised as a line on one particular quote — and forgetting to build that recovery in is one of the most common reasons a busy construction business ends up with little real profit.
Key takeaways
- Overheads are the costs of running the business itself, not tied to any one job — rent, admin, insurance, software, vehicles and marketing.
- Overheads differ from on-costs, which sit on a specific worker’s wage, and from preliminaries, which belong to one particular project.
- Overheads are usually recovered as a percentage added on top of direct job costs, not itemised line by line on a client-facing quote.
- Margin and overhead recovery are related but not the same thing — a margin has to cover overhead first, then leave genuine profit on top.
- Underestimating overhead is one of the fastest ways a fully booked business still ends the year with little to show for it.
What Counts as an Overhead
Overheads are the day-to-day cost of the business existing, whether or not a single job is currently running. They sit apart from labour, material and plant costs charged to a specific project, and apart from the on-costs attached to a specific worker’s wage.
- Office or yard rent, utilities and rates
- Administration, bookkeeping and management wages
- Business insurances — public liability, professional indemnity
- Software and subscriptions, including estimating and job management tools
- Vehicle and fuel costs not billed directly to a job
- Marketing and business development
- Accounting, legal and other professional fees
- Licensing, registration and compliance costs
Overheads vs On-Costs vs Job Preliminaries
These three terms get mixed up constantly because they all sit above the bare cost of materials, but each is tied to a different thing. On-costs are tied to a specific employee’s wage — superannuation, workers compensation, leave. Preliminaries are tied to a specific job or site — the site shed, temporary fencing, site supervision for that project. Overheads are tied to the business as a whole, and get spread across every job rather than charged to just one.
| Cost type | Tied to | Example |
|---|---|---|
| On-costs | A specific worker’s wage | Superannuation, workers compensation, leave loading |
| Preliminaries | A specific job or site | Site shed, temporary fencing, site supervision |
| Overheads | The business as a whole | Office rent, admin wages, insurance, software |
How Overhead Is Recovered in a Quote
The typical approach is to total up annual overhead costs, then divide that figure across expected annual revenue or billable hours to arrive at an overhead recovery percentage. That percentage is then added on top of the direct cost of each job — labour, material, plant and preliminaries — before a separate profit margin is added on top again.
A quick worked example
Annual overhead costs of 180,000 dollars against annual revenue of 1,200,000 dollars works out to a 15 per cent overhead recovery rate — added to the direct cost of each job before profit margin is applied on top.
Why Forgetting Overhead Erodes Real Profit
A business that prices jobs off labour and material costs alone, without a built-in overhead recovery percentage, can look profitable job by job while quietly running at a loss overall — because the real cost of keeping the office running, the insurance current and the software subscriptions paid never gets charged to any job at all.
MTH’s editable rates library lets an overhead recovery percentage be built into rate and margin settings once, so every job quote already carries its fair share of the real cost of running the business — rather than relying on remembering to add it back in manually, job after job.
Frequently asked questions
What is the difference between overheads and on-costs?
On-costs are the additional employment expenses tied to a specific worker’s wage, such as superannuation and workers compensation. Overheads are the broader running costs of the business as a whole — rent, admin, insurance, software — that get spread across every job rather than tied to one worker or one project.
What percentage should I add for overheads?
There is no single correct figure — it depends on the actual size of your annual overhead costs relative to revenue. Calculating your own overhead recovery rate from real numbers, rather than copying a generic industry percentage, gives a far more accurate result.
Are overheads the same as margin?
No. Overhead recovery covers the real cost of running the business, while margin is the profit added on top once overhead is already covered. A margin that only accounts for profit and ignores overhead will leave the business short even on jobs that look profitable.
Do overheads include vehicle costs?
Vehicle and fuel costs not billed directly to a specific job are generally treated as overhead, since they support the running of the business as a whole rather than one project.
How do I calculate my overhead recovery rate?
Total your actual annual overhead costs, then divide that figure by your expected annual revenue or billable hours to get a recovery percentage, which is then added on top of direct job costs before profit margin is applied.
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