Change Order Auditor

Stop paying for change orders
nobody approved.

Contractors submit COs with inflated labor rates, markup cap violations, unauthorized markup layers, and sometimes straight-up math errors. ChangeSet AI catches every one — before you sign.

Get the Full Kit → See How It Works

Built on real KJL Consulting Group audit data

CO-012 Audit — ABC Mechanical HIGH RISK

#	Description	Submitted	Benchmark	Risk
1	Duct reroute	$3,380	$3,380	LOW ✓
2	Labor — 24 HR @ $310	$7,440	$6,480	RATE ✗
5	Overhead (15% vs 10% cap)	$1,913	$1,178	CAP ✗
7	Sub-sub markup (unauthorized)	$308	$0	REJECT

KJL Counteroffer $14,406 — Save $4,044

The CO Problem

Contractors count on you not checking.

Every CO is a negotiation. Most OPMs approve them as-submitted because auditing takes time they don't have. Contractors know this. ChangeSet AI gives you the leverage back.

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Labor rate overbills

The contract says $270/HR journeyman. The CO bills $310/HR — no breakdown, no justification, just a blended rate hoping you won't check.

↑ $40/HR × 24 hours = $960 overcharge

📋

Markup cap violations

The subcontract caps overhead at 10% and profit at 5%. The CO applies 15% and 10% — doubling your markup exposure on every CO in the project.

↑ $735 OH overcharge + $833 profit overcharge

🔗

Unauthorized markup layers

A "sub-sub markup" or "management fee" buried in the CO — the contract is silent on it, which means it's not authorized. But it still gets approved.

↑ $308 rejected — contract doesn't permit it

🔢

Arithmetic errors (in your contractor's favor)

The line items add to $16,753. The invoice says $18,442. Nobody caught the $1,689 gap until the AI did — and it happened on a real KJL project.

↑ $1,689 unexplained gap — rejected pending explanation

The 10-Step Audit Workflow

A real owner's rep audit — powered by AI.

ChangeSet AI walks you through the same change order review process KJL uses on every project. Paste in your CO details and contract terms. Get a full audit report and a ready-to-send contractor email.

Document Intake

Log what the contractor submitted — CO line items, supporting backup, whether the executed subcontract and labor rate schedules are on file.

FOUNDATION

Contract Term Extraction

Pull the governing terms: labor rate by classification, overhead cap, profit cap, and whether sub-sub markup is authorized. These are your audit controls.

CONTROLS

CO Parsing + Arithmetic Check

Parse every line item and check the contractor's own math. Unexplained gaps between line-item subtotals and the invoice total are flagged immediately.

CATCHES ERRORS

Scope Validation

Is each line item actually a change order, or is it already in the base contract scope? Flag items for VALID CO, IN BASE CONTRACT, INSUFFICIENT BACKUP, or REJECT.

CATCHES SCOPE CREEP

Cost Reconstruction

Rebuild the CO using contract-approved rates for every labor classification. Establish the KJL benchmark direct cost before markups are applied.

CATCHES RATE OVERBILLS

Markup Validation

Check overhead %, profit %, and any additional markup layers against the contract caps. Flag every violation with the specific contract clause and the dollar impact.

CATCHES MARKUP VIOLATIONS

Variance Analysis

Submitted vs. KJL benchmark by line item and in total. Risk tier assigned: LOW (<10%), MEDIUM (10–25%), HIGH (>25%). Triggers escalation at the right threshold.

RISK TIERING

7–8

Line Item Commentary + Output Table

Full written commentary for each line item. Structured output table with all flags, benchmarks, and variances — formatted for Excel export or client reporting.

AUDIT REPORT

Summary Report + Disposition

Financial summary, scope summary, markup summary, negotiation position, and a clear disposition: APPROVE / NEGOTIATE / REJECT. Backed by contract evidence, not opinion.

DECISION READY

Contractor Response Email

A ready-to-send written response citing specific contract violations, your approved amounts, and a response deadline. No vague pushback — just contract-backed, professional notice.

SEND TODAY

Violation Detection

Five ways contractors overbill. ChangeSet catches all five.

Every violation type below comes from a real KJL change order audit. These aren't edge cases — they show up on projects across residential, commercial, and institutional work.

⚡

Labor Rate Violations

Submitted rate doesn't match the executed subcontract. Often a blended rate billed at foreman or general foreman level with no classification breakout.

CO-012: $310/HR billed vs. $270/HR journeyman rate → $960 overcharge

📊

Overhead Cap Violations

The subcontract caps overhead at 10%, 12%, or 15%. The CO quietly applies 5 points more and assumes you won't notice on a multi-line submission.

CO-012: 15% billed vs. 10% cap → $735 reduction on corrected direct cost

💰

Profit Cap Violations

Profit applied at double the contract cap — applied to the wrong basis, or stacked incorrectly. Often the largest single recovery per CO.

CO-012: 10% profit billed vs. 5% cap → $833 reduction

🔗

Unauthorized Markup Layers

Sub-sub markup, management fee, coordination overhead — contract is silent, which means not authorized. Every dollar of an unauthorized layer is recoverable.

CO-012: $308 sub-sub markup rejected — no contract basis

🔢

Arithmetic Errors

When the contractor's own math doesn't reconcile to the invoice total, that gap has no line item — and no line item means no payment. ChangeSet finds the gap.

CO-012: $1,689 gap between line-item subtotals and invoice total → rejected

📄

In-Scope Items Billed as Changes

Work already included in base contract scope gets repackaged as a change order. ChangeSet validates each line item against contract scope before any pricing review.

Base contract scope, patching, or coordination overhead billed as extra work

Real Results — CO-012

$18,450 submitted.
$14,406 approved.

AHU relocation on a commercial floor, mechanical subcontractor, four separate pricing violations. All scope was legitimate — the dispute was entirely about rates and markup compliance. ChangeSet AI caught every violation.

✓ $4,044 recovered (28.1% reduction) — single CO

⚡

Labor Rate Overbill

$310/HR submitted vs. $270/HR journeyman rate in executed subcontract. 24 hours billed as a single blended rate — $960 recovered.

📊

Overhead Cap Violation

15% billed vs. 10% contract cap. Applied to corrected direct cost of $11,780 — $735 recovered.

💰

Profit Cap Violation

10% profit billed vs. 5% contract cap — double the allowed rate. $833 recovered.

🔗

Unauthorized Markup + Arithmetic Gap

$308 sub-sub markup rejected (no contract authorization). $1,689 arithmetic gap — contractor's own line-item math didn't reconcile to their invoice total.

CO-012 Audit Summary — ABC Mechanical

CO Submitted $18,450

KJL Benchmark $14,406

Total Variance +$4,044 (28.1%)

Risk Level HIGH

Violations Found 4 distinct violations

Scope Disputes Zero — all scope valid

Disposition NEGOTIATE

Contractor Email Ready to send

KJL Position

"Counter at $14,406. All direct scope is valid but four identifiable violations total $4,044. Issue written response citing contract terms before any CO execution."

The ChangeSet AI Full Kit

Everything you need to audit your first CO today.

Built from a real KJL change order audit. Each piece of the kit maps to a stage of the 10-step workflow — so you're not learning a new system, you're running one that already works.

📋

10-Step CO Audit Prompt Library

Sequential prompts covering all 10 audit stages — from document intake through the contractor email. Paste your CO, paste your contract terms, and follow the prompts. Works with any AI model.

.MD — Works with ChatGPT, Claude, Gemini

📊

CO Log Tracker

Track every CO across a project: submitted amount, KJL benchmark, variance, risk tier, disposition, and status. Built in Excel, Copilot-compatible, structured for owner reporting.

.XLSX — Excel + Microsoft Copilot

📄

Full Sample Audit — CO-012

The complete real-world audit report from KJL's CO-012 review — all 10 steps, the output table, the variance analysis, and the contractor email. Use it as a reference or a template.

.MD — Real KJL Project Data

🖥️

CO Auditor Review Tool

An interactive browser-based tool for walking through the audit workflow. Input your CO data, run each audit stage, and export your findings — no software install required.

.HTML — Open in any browser

Pricing

Start free. Upgrade when you're ready.

The free tier gets you the prompt library and the sample audit. The Full Kit adds the Excel tracker, the interactive review tool, and lifetime updates.

Free

Starter

The CO audit methodology and a real sample report — enough to run your first audit today.

10-Step Audit Prompt Library (.md)
Sample Audit Report — CO-012
Works with ChatGPT, Claude, Gemini
CO Log Tracker (.xlsx)
Interactive CO Review Tool (.html)
Lifetime updates

Download Free →

AI tools built by
real owner's reps
for real projects.

KJL Consulting Group is a WBE-certified owner's representative and construction PM firm based in NYC. Every tool in the Build Intelligence suite is built from real KJL project data — not demos, not hypotheticals. If it's in the tool, it happened on a project.

Follow the build on Instagram @coffee.and.construction.

⚖️

LevelSet AI

AI-powered bid leveling — apples-to-apples contractor comparison

📋

ChangeSet AI

AI-powered change order auditor — catch violations before you sign

🔮

More coming soon

More tools from the Build Intelligence "Set" family

FAQ

Questions about ChangeSet AI

No. The prompt library gives you the exact text to paste into ChatGPT, Claude, or Gemini — one stage at a time. You paste your CO, you paste your contract terms, and the prompts do the rest. If you can copy and paste, you can run a CO audit.

The audit still works. Step 0 and Step 1 document what you have and what's missing. If you only have the key terms verbally or from a summary sheet, you input those — the AI applies them as governing authority and flags missing documents for follow-up. Just like a real owner's rep would.

Yes — the workflow applies to any project type where you have a signed contract with rate and markup terms: ground-up residential, commercial TI, institutional, multifamily. The same violations happen on a gut renovation that happen on a $10M commercial project.

Any modern AI model — ChatGPT (GPT-4 or later), Claude (Sonnet or Opus), Google Gemini. The prompts are written in plain language and don't require any special model features or API access. Open a chat, paste the prompt, paste your data, and go.

That's a real number from a real KJL project (CO-012, mechanical sub, commercial floor renovation). It's not a guaranteed outcome — CO size, trade, and how well the contractor follows the contract all vary. What's consistent is that most COs have at least one pricing issue that goes unchallenged. ChangeSet AI finds it.

Not for reversing executed COs — those are done. But you can use ChangeSet AI to audit future COs from the same contractor on the same project, or to set the right precedent before the next one comes in. Running an audit once changes the dynamic for every CO that follows.

No. It's a one-time purchase via Gumroad. You get instant access to all files — the prompt library, CO log tracker, sample audit report, and interactive review tool — plus all future updates at no additional cost.

Stop paying for change ordersnobody approved.