Change orders are not a sign of a troubled project. They're a normal part of construction — design evolution, unforeseen conditions, owner preference changes. On a typical commercial project, change orders add 5–15% to the original contract value. The question isn't whether changes will happen. It's whether the contractor will be paid for them.
This guide covers every step of change order management — what triggers them, what notice requirements apply, how to price them using actual cost data from a construction time tracking app, how to get them approved, and how to protect payment when owners resist.
This guide explains how to manage construction change orders properly — from notice requirements to pricing, documentation, approval, and dispute protection using GPS timesheets for contractors.
A change order is required any time the scope, schedule, or cost of the contracted work changes. Triggers include:
Owner-Directed Changes Owner requests additional scope, different materials, modified design, or accelerated schedule. The most common trigger. The risk: owners often expect "small" changes to be absorbed without additional cost.
Architect/Engineer Directives A/E issues a clarification, RFI response, or supplemental instruction that adds scope, requires different installation methods, or changes specified materials. The legal question: is this interpretation of the contract (contractor bears cost) or new scope (change order warranted)?
Differing Site Conditions Conditions encountered in the field materially different from what the contract documents represented — unexpected subsurface rock, undisclosed utilities, undocumented hazardous materials, concrete in different locations than drawings showed.
Design Errors and Omissions Contract documents contain errors, omissions, or conflicts that require field resolution. Contractor discovers that mechanical drawings conflict with structural drawings, or that a specified product is unavailable and requires substitution.
Code Changes Building code or regulatory requirement changes between design and construction that require modifications to the work.
Unforeseen Conditions in Existing Buildings Renovation projects frequently encounter conditions not visible until demolition — asbestos, lead paint, concealed structure that conflicts with new work, pre-existing defects in building systems.
Owner-Caused Delays When owner actions cause schedule compression for remaining work, the acceleration cost (overtime, added supervision, resequencing) is a compensable change. See Construction Project Delay for delay cost analysis and change order preparation.
Proper documentation through construction photo documentation software strengthens entitlement.
Failure to give timely notice is the most common reason valid change order claims are denied.
Most construction contracts require the contractor to give written notice of a claim or potential change order within a specific number of days of discovering the triggering event — typically 7, 14, or 21 days. If notice isn't given within that window, the contractor may waive the right to additional compensation regardless of how legitimate the underlying claim is.
Notice requirements vary by contract:
|
Contract Type |
Typical Notice Period |
Format |
|---|---|---|
|
AIA A201 |
21 days from discovery |
Written |
|
ConsensusDocs 200 |
21 days |
Written |
|
Federal government (FAR) |
Promptly / before work if possible |
Written |
|
Custom owner contracts |
7–14 days (often shorter) |
Written — sometimes certified mail |
What notice must include:
Notice is not a change order. It's a reservation of rights — a formal statement that the contractor believes this event entitles them to additional compensation and that a change order will follow. Courts and arbitrators treat notice as a threshold issue: no notice, no claim, regardless of merit.
Daily reports are the first line of notice documentation. An entry on the day a verbal direction is given — "Owner directed contractor to install [specific scope] not included in contract documents. Contractor advised this constitutes additional scope; written direction requested. Proceeding at owner's direction." — establishes notice was contemporaneous. See the Construction Daily Report for how to document change order triggers in the daily record.
See How to Negotiate a Construction Contract for notice clause negotiation — owner-favorable contracts often shorten notice windows to 7 days or require certified mail, creating traps for contractors who don't read carefully.
Direct Labor Actual hours worked on the change order scope × burdened labor rate. This is where construction employee time tracking becomes critical — workers clocked into a change order cost code produce timestamped, GPS-verified records of every hour worked on the changed scope.
Materials Actual material cost from invoices and delivery receipts. Include waste factors, tax, and delivery. If materials were purchased specifically for the change, the invoice is the supporting document.
Subcontractor Costs Sub's price for the changed scope. Include GC coordination markup (typically 10–15%) covering submittal management, schedule coordination, and payment processing.
Equipment Rental quotes or internal equipment rates for equipment required specifically for the change scope. Include operator labor separately in the labor calculation.
General Conditions Impact Changes that extend project duration add general conditions cost — extended superintendent time, extended temporary facilities, extended insurance and bond costs. Duration-based changes must include this component or they're underpriced.
For a deeper breakdown of delay-driven claims, see this construction project management guide.
Change order markup should match or exceed base contract markup for three reasons:
Standard change order markup structure:
|
Component |
Rate |
|---|---|
|
Direct costs (labor + materials + equipment) |
Cost + 15–25% |
|
Subcontractor costs |
Cost + 10–15% |
|
GC overhead on above |
10–15% |
|
GC profit |
5–10% |
Many contracts cap change order markup — review the contract before the project starts, not when the first change arrives.
Fixed-price change order: Contractor prices the scope, owner approves, work proceeds at that price. GC bears cost risk if actual costs exceed the estimate. Preferred when scope is well-defined.
Time and materials (T&M): Work proceeds at actual cost (labor hours + material invoices + equipment) plus an agreed markup percentage. Owner bears cost risk. Preferred when scope isn't fully defined at time of direction.
T&M change orders require real-time documentation:
A construction timesheet app that captures GPS-verified hours by cost code produces the timestamped labor record that backs T&M billing. Daily T&M tickets signed by the owner's rep that day are far stronger than unsigned summaries submitted weeks later.
CHANGE ORDER PROPOSAL Project: ___________________ CO #: ______ Date: __________ Change Description: _______________________________________ Triggering Event: _________________________________________ Reference (RFI/ASI/Owner direction): _____________________ DIRECT COSTS Labor: Trade: ____________ Hours: ____ Rate: $____/hr = $______ Trade: ____________ Hours: ____ Rate: $____/hr = $______ Labor subtotal: $______ Materials: Item: _____________________ Qty: ____ Unit: $__ = $______ Item: _____________________ Qty: ____ Unit: $__ = $______ Materials subtotal: $______ Subcontractor: Sub: ______________________ Scope: ______________ = $______ Materials subtotal: $______ Equipment: Type: _________________ Duration: ___ Rate: $__ = $______ DIRECT COST SUBTOTAL: $______ OVERHEAD AND PROFIT GC Overhead (___%) $______ GC Profit (___%) $______ TOTAL CHANGE ORDER AMOUNT: $______ SCHEDULE IMPACT: ☐ No schedule impact ☐ _____ calendar days extension requested Supporting documents attached: ☐ Time records ☐ Material invoices ☐ Sub quote ☐ Daily reports ☐ Photos ☐ RFI/ASI Change is identified in the field. Foreman documents in daily report — specific scope, owner direction, date. Notice given per contract requirements.
Contractor prepares CO proposal with scope description, cost breakdown, and schedule impact. Target: submit within 7–14 days of the triggering event (even if the contract allows more time — delay weakens the claim and delays payment).
Owner and/or A/E reviews the proposal. They may:
If the owner rejects a legitimate change order claim: document the rejection in writing, notify the surety if bonds are involved (see Construction Bonds Guide), and preserve the claim for dispute resolution while continuing to document costs.
Owner and contractor execute the written change order — signed by both parties, specifying:
An unsigned change order is not a change order — it's a proposal. Work under an unsigned change order at the contractor's risk.
Once executed:
Maintain a change order log for every project. Minimum fields:
|
CO # |
Description |
Date Submitted |
Amount Requested |
Status |
Date Approved |
Amount Approved |
Date Billed |
Date Paid |
|---|---|---|---|---|---|---|---|---|
|
001 |
Additional waterproofing |
3/14 |
$8,400 |
Approved |
3/22 |
$8,400 |
4/1 |
4/28 |
|
002 |
Owner-directed wall relocation |
3/28 |
$12,600 |
Under review |
— |
— |
— |
— |
|
003 |
Unforeseen underground utilities |
4/5 |
$31,200 |
Disputed |
— |
— |
— |
— |
Review the change order log weekly. Unanswered proposals older than 14 days need follow-up. The log also tracks total pending change order value — critical for Construction Cash Flow Management because approved but unpaid change orders are receivables that affect liquidity.
When a change order is disputed, the dispute comes down to evidence:
Construction time tracking for workers provides the most defensible labor evidence available:
A T&M change order dispute scenario:
Owner disputes 48 hours of labor on a T&M change order, claiming the work took no more than 32 hours. Construction employee time tracking app records show:
That's a nearly unassailable claim. The owner's 32-hour assertion is verbal, unsupported by any documentation. The contractor wins.
Executing undocumented scope verbally directed by the owner. "The owner told me to do it" is not a change order. Do it, document it, notice it, price it, get it signed.
Missing notice deadlines. The contract said 14 days. The contractor waited 3 weeks. The legal right to additional compensation may be waived — regardless of the legitimacy of the underlying claim.
Underpricing change orders to avoid conflict. Cutting markup or excluding overhead on changes to keep the owner happy produces negative-margin change order work. The goodwill rarely translates into more favorable treatment on future changes.
Not pricing schedule impact. A change order that adds 3 weeks to the project duration has a general conditions cost — extended superintendent, extended site facilities, extended insurance. Changes priced without duration impact are underpriced.
Not tracking change order costs separately. T&M work mixed into the base contract labor codes produces an unauditable record. A separate cost code for every change order enables exact cost documentation. The construction time clock app makes this practical — workers select the CO cost code at clock-in.
Not following up on pending approvals. A change order submitted and never followed up may sit unsigned for months. Review the log weekly. Unanswered proposals past 14 days get a written follow-up. Unanswered past 30 days get a formal notice.
Ignoring retainage on change orders. Change orders are typically subject to the same retainage percentage as the base contract. A $50,000 change order on a 10% retainage contract has $5,000 withheld until final payment. Factor this into cash flow projections. See Construction Retainage.At triggering event:
Pricing:
Approval:
Documentation:
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