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Construction Job Costing: A Practical Guide for Builders

Budget vs. committed vs. actual, why the difference matters, and how to track real cost per job so you know a project's margin before the final invoice — not after.

Daniel Boucher · Construction Technology WriterJul 7, 20269 min read

Most builders find out a job lost money when the final invoice lands. By then it's history. Job costing is how you know where a project stands while you can still do something about it — and it comes down to three numbers most software gets wrong.

Budget, committed, and actual — know the difference

Your budget is what you quoted. Committed cost is money you've obligated but not yet paid — the purchase orders you've issued to suppliers and subs. Actual (billed) cost is what approved vendor bills have added. Remaining budget is what's left after actual cost. If your software only shows budget and a made-up "spent" figure, you're flying blind on the two numbers that predict trouble.

  • Budget — the number you contracted to build for
  • Committed — open purchase orders not yet billed
  • Actual — approved vendor bills, your real cost to date
  • Remaining — budget minus actual

Tie purchase orders and bills to the job

Committed cost is invisible without purchase orders. Issue a PO to a supplier against a specific job, and that job's committed cost updates immediately — so a $30,000 material order is on the budget before it's billed, not after. When the vendor bill arrives, match it to the PO and approve it, and it becomes actual cost that reduces remaining budget in real time.

Protect margin with change orders

Scope creep is where residential margin dies. Every verbal "sure, we can do that" is money given away unless it becomes a priced, approved change order that updates the contract and the budget. Job costing only tells the truth if every change flows into it.

How BuildersBridge helps

BuildersBridge shows every active job as one live row: budget, committed cost from open POs, actual cost from approved bills, and remaining. Approve a vendor bill and the remaining-budget figure moves the same second. Purchase orders, vendor bills, and approved change orders all roll into the number automatically, so you know a job's margin throughout the build — not at the end of it.

Try BuildersBridge

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