Construction
Job costing in construction: how to know the real margin of every job
The company P&L closes positive while two specific jobs drain the cash. Without job costing, you see neither of them.
Job costing means separating revenue and cost by job, instead of dumping everything into one expense account. Without it, the company P&L can close positive while two or three specific jobs eat the profit from the others, and nobody notices until payroll is short. With job costing in QuickBooks, each job becomes a project with revenue, material, labor and subcontractors separated, and the margin of each one closes every month.
For builders in Florida, where hurricanes and schedules hit cash directly, see also construction bookkeeping in Florida.
Why the company P&L hides the problem
Picture a builder that closed the year with 1.2 million in revenue and a 9 percent margin. Looks healthy. Now break that number down by job.
| Job | Revenue | Cost | Margin |
|---|---|---|---|
| Residential remodel A | 320k | 246k | 23% |
| Commercial B | 410k | 336k | 18% |
| Remodel C | 180k | 191k | minus 6% |
| Addition D | 290k | 319k | minus 10% |
The first two jobs carried the year. The last two gave back a good part of what they earned. On the consolidated P&L this shows up as a 9 percent margin and nothing else. The owner closes the year thinking the business yields 9 percent, when in reality what he does well yields 20 and what he does badly loses money.
The decision he makes the following year with that information is wrong by construction: he will keep taking both types of job.
What to separate in every job
Job costing is not just tagging an expense with the job name. It is separating by nature, because each nature behaves differently and has a different owner.
- Material. The easiest to tie out and the one that blows up most from unbudgeted purchases.
- In house labor. Needs hour tracking per job, otherwise the cost sits entirely in a generic payroll account.
- Subcontractors. Usually the biggest line and the messiest, because payment goes out by check or transfer with no link to the job.
- Equipment and rentals. Crane, dumpster, scaffolding. An item sitting idle on site is cost running with no output.
- Permits and fees. Small in value, but when not tied to the job it distorts comparison between projects.
- Rework. Worth isolating. It is the cost nobody budgets and the one that best explains a job that turned into a loss.
How this works in QuickBooks
QuickBooks has a projects feature, which is where job costing happens. The minimum structure that works is this.
- Each job becomes a project, with a name the crew recognizes, not an internal code.
- The chart of accounts separates direct job cost from company overhead.
- Every cost transaction gets the project assigned at entry, not at month end.
- Job revenue is recognized in the same project, so the margin makes sense.
- The profitability by project report joins the monthly close, next to the P&L.
Reconciling with Buildertrend
Anyone using Buildertrend already enters budgets, change orders and purchases by job in there. The classic problem is that this data lives apart from the books, and the two sides never match.
The fix is to treat each system for what it does best. Buildertrend stays the source for job operations, QuickBooks stays the source for accounting, and there is a periodic reconciliation between them. That way you do not enter data twice and do not live with two different numbers for the same job.
Buildertrend and QuickBooks: who owns what
The most expensive mistake in construction is not picking the wrong system. It is using both systems for the same thing. Buildertrend and QuickBooks overlap in several places, and when nobody decides which one is the source of truth for each piece of information, you end up with two different numbers for the same job and neither one deserves trust.
The split that works is simple: Buildertrend is the job system and QuickBooks is the money system. Everything that describes execution lives in Buildertrend. Everything that becomes an accounting entry lives in QuickBooks. The bridge between them is a single one, and it runs in one direction.
| Information | Source of truth | Why |
|---|---|---|
| Budget and change orders | Buildertrend | It is where the client approves and where scope changes |
| Hours worked per job | Buildertrend | Time is logged in the field, not in the office |
| Vendor bill | QuickBooks | It becomes accounts payable and hits cash |
| Client invoice | Buildertrend, booked in QuickBooks | Billing follows the job schedule, the record follows the accounting basis |
| Margin per job | QuickBooks | Only there is real cost reconciled against the bank |
The rollout order that avoids rework
Turning the integration on before fixing the foundation is the fastest way to duplicate entries. The order that works has four steps and takes a few weeks, not months.
- First, the chart of accounts. Direct cost separated from overhead, with the cost categories you actually use: material, labor, subcontractor, equipment and permits.
- Then, the job list. Each job becomes a project in QuickBooks with the exact name it has in Buildertrend. Different names on each side break reconciliation forever.
- Only then the integration. With the foundation ready, what moves between systems lands in the right place with nobody correcting it afterward.
- Last, the monthly close. Every month someone compares Buildertrend cost with QuickBooks cost, job by job. That check is what keeps both numbers equal.
The three sync mistakes that show up most
The first is entering the same bill manually in both systems, which doubles job cost and erases the margin. The second is creating a new job only in QuickBooks after the integration is already running, which drops cost in one project and revenue in another. The third is treating a client deposit as revenue the day it arrives, when it is still a liability: the job looks profitable in the month of the deposit and unprofitable in the months when material is bought.
Subcontractors, W-9 and 1099
This is the line that causes the most headaches in January, and the cause is always the same: the payment happened, the paperwork did not. The routine that prevents it has three simple rules.
- W-9 before the first payment. No exceptions. Once the work is done, the odds of getting the document drop sharply.
- Payment always tied to the job. A loose check with no reference is a cost that exists and shows up on no job at all.
- Year to date total per contractor. That is what defines who needs a 1099, and checking it in January is late.
What changes after three months of job costing
The gain is not the report, it is what the report lets you decide. After a quarter with cost separated by job, three things change.
- Quoting stops being a guess. You start quoting with the real cost from your own history, not a rule of thumb percentage.
- You learn to say no. It becomes clear which type of job, which value range and which client profile consistently loses money.
- Correction happens mid job. With margin tracked monthly, you can renegotiate scope or a change order while the contract is still open.
Frequently asked
Questions on this topic
Does job costing work for a small builder?
It does, and strictly speaking that is where it matters most. A small builder has no cushion to carry a losing job, and is exactly the one that usually lacks the information. With three to five simultaneous jobs the control is already simple to maintain.
Do I need to switch from Buildertrend to QuickBooks?
No. They have different functions and should coexist. Buildertrend is the job management system, QuickBooks is the financial system. What has to exist is reconciliation between them, so there are not two numbers for the same job.
How do I tie employee hours to a job?
With hour tracking per job, which can come from Buildertrend itself or from a simple time clock. Without it, in house labor sits entirely in a generic payroll account and margin per job comes out incomplete.
What about jobs that already finished?
They can be rebuilt, as long as statements and invoices from the period exist. It is usually worth rebuilding the last three to six jobs, because that sample reveals the pattern of what makes money and what does not.
Keep reading
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Job costing, subcontractors and margin per job in QuickBooks.
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The path when the close is months behind.
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The five variables that set the price.