A change order in construction is a written amendment to the construction contract that adjusts the contract sum, the contract time, or both, and takes effect once the owner, contractor, and architect sign it. It records agreed changes to the scope of work so the original agreement stays accurate.
No building gets built exactly as drawn. Soil turns out softer than the report suggested, a client asks for a wider opening, a light fixture goes out of production. Each of those has to be priced, timed, and written down before anyone picks up a tool.
What a Change Order Actually Changes
Three things sit inside a construction contract: the scope of work, the contract sum, and the contract time. A change order can touch any combination of them. Adding a rooftop terrace changes all three. A certified equal substitution might move only the sum. A weather suspension moves only the time.
Most US projects use the American Institute of Architects form for this. AIA Document G701, currently in its 2017 edition, records the change in the work and the adjustments to sum and time, with signature blocks for owner, architect, and contractor. Article 7 of the A201 General Conditions sets out three routes: the change order, the construction change directive, and the minor change issued by the architect that carries no cost or time effect.
That third route matters. Clarifying a dimension needs no change order, and treating every field question as a paid extra is the fastest way to sour a job.
Why Change Orders Happen
The causes cluster into five familiar groups, and knowing which one you are dealing with usually determines who pays.
Owner-requested changes are the cleanest case: the client wants something different from what was contracted, so the cost is theirs and the only argument is the number. Design gaps and conflicts are messier, covering a beam that collides with a duct, a door schedule that disagrees with the plan, or a detail that was never drawn. Unforeseen site conditions bring buried foundations, rock, and contaminated fill. Regulatory changes arrive when a code amendment lands mid-construction. Material availability closes the set, and lead times have made it a far more common trigger than it was a decade ago.
Public contracts formalize several of these. Federal-aid highway work must carry changed-condition clauses under 23 USC 112(e) covering differing site conditions, suspensions of work ordered by the engineer, and significant changes in the character of work, a useful checklist even on private jobs.
📌 Did You Know?
A Construction Industry Institute study run with Oklahoma State University researchers examined 106 projects worth $3.9 billion across 23 companies and named the ripple effect as a distinct risk: projects where one change triggers a chain of successive changes show worse cost and schedule growth than those with the same number of isolated changes.
From RFI to Signed Change Order
Most changes start as a question, not a claim. The contractor hits something the documents do not answer and issues a request for information. If the architect's answer stays inside the contracted scope, the RFI closes and nothing else happens.
If the answer adds work, the path continues. The architect or owner issues a proposal request describing the revised scope. The contractor prices it, breaking out labor, material, equipment, subcontractor costs, and markup. The architect reviews that pricing against the contract's limits, the owner accepts or negotiates, and the agreed change is signed onto a change order. Keeping the RFI log linked to the change order log is what makes any of this traceable later.
💡 Pro Tip
Give every potential change a number the day it appears, before anyone knows whether it will be paid. A pending log carrying "PCO-014, slab thickening at grid F, price not yet received" costs nothing to maintain and turns a vague argument at closeout into a dated record.
Change Order vs Construction Change Directive
The two get confused constantly, and the difference is simply whether the parties have agreed yet. A change order records an agreement. A directive gets work moving when there is none.
AIA guidance on how a construction change directive differs from a change order puts it plainly: the directive is a written order prepared by the architect and signed by the owner telling the contractor to proceed before the cost or schedule impact has been settled. The contractor must proceed anyway. Pricing follows through the methods in the owner-contractor agreement, or through the architect's determination from documented costs. Once agreed, the directive converts into a change order.
How the Two Compare
| Aspect | Change Order (G701) | Change Directive (G714) |
|---|---|---|
| Cost and time | Settled before signing | Not yet settled |
| Who signs it | Owner, architect, contractor | Owner and architect initially |
| When it is used | Scope and price both resolved | Work cannot wait for the price |
| Contractor obligation | Proceeds on agreed terms | Must proceed with directed work |
| Effect on the contract | Adjusts sum and time at once | Interim, converted later |
| Basis of pricing | Negotiated before execution | Contract methods or documented costs |
What Belongs on the Document
A change order that cannot be read on its own two years later has failed. Four elements carry the weight: a description specific enough to identify the physical work, with revised drawings referenced by number and date; a cost breakdown showing labor, materials, subcontractor quotations, and markup; the schedule effect stated explicitly, including a plain "no change to the contract time" when that applies, because silence on time is how delay claims get built; and dated signatures from every party the contract names.
Owner-side procedures add their own controls. The University of Alabama's construction change order policy states that no actual work begins and no funds are spent until the change order request approval form has been approved, and it requires consent of surety once total changes exceed 10 percent of the revised base contract amount. Knowing an institutional client's internal route matters as much as knowing the contract form.
How Change Orders Get Priced
Three methods cover almost everything. A lump sum works when the scope is defined and the contractor can carry the risk of misjudging quantity. Unit pricing suits work whose type is known but whose quantity is not, such as rock excavation at a fixed rate per cubic yard. Cost plus a fee fits work that has to start before it can be quantified, which is exactly the situation a directive creates.
Markup percentages for overhead, profit, and subcontractor work should have been fixed at contract signing. Arguing about them while a crew waits is a losing position for everyone.
Where the Architect Sits
The architect evaluates changes, prepares directives, certifies amounts, and signs the change order, but does not authorize spending. That decision belongs to the owner, a distinction worth explaining to a client early rather than during a dispute.
Design-caused changes are the uncomfortable category. When a change stems from an error or omission in the documents rather than an owner request or an unforeseen condition, the conversation moves toward professional liability, the exposure that professional indemnity insurance exists to cover. Recording which changes came from betterment and which from correction is risk management, not bookkeeping.
⚠️ Common Mistake to Avoid
Telling a contractor on site to "go ahead, we will paper it later" is the most expensive habit in contract administration. Verbal instructions create work that has been performed but not authorized, weakening the owner on price and the architect on authority. If work genuinely cannot wait, issue a construction change directive the same day.
Reducing the Number You Have to Write
Changes caused by owners and by ground conditions are largely outside your control. Changes caused by the documents are not. Running clash detection across the architectural, structural, and MEP models before issuing for construction removes field conflicts that would otherwise arrive as priced extras. Resolving detail drawings so a trade can build from them without guessing removes another set.
Upstream of all of it sits scope definition. A vague design brief produces a vague contract, and a vague contract makes almost anything arguable as an extra. Regular site visits close the loop, since a deviation caught during rough-in costs a fraction of the same one caught after finishes. A ready set of essential resources for architects also saves rebuilding logs and forms on every new job.
Putting It All Together
Bottom line: a change order is not an admission that something went wrong, it is the contract staying honest about what is actually being built. The projects that suffer are the ones where changes happened without paperwork, without pricing, and without a dated record of who asked for what.
Contract forms, approval thresholds, and change procedures vary by jurisdiction and by the agreement in force on your project. Check the terms of your own contract and consult a qualified professional before relying on any general procedure.
Frequently Asked Questions
Who Pays for a Change Order?
It depends on the cause. Owner-requested scope and genuinely unforeseen site conditions are normally the owner's cost, while changes arising from a contractor's error or defective work are the contractor's. Changes traced to errors in the design documents are negotiated and may involve the design team's professional liability cover.
Can a Contractor Refuse a Change Order?
A contractor can decline to sign if the proposed price or time adjustment is unacceptable, since a change order is an agreement. What a contractor generally cannot do under standard general conditions is refuse work directed through a construction change directive.
Is a Change Order the Same as a Variation?
They describe the same idea in different contract traditions. "Change order" is standard in US practice under AIA and similar forms, while "variation" is the equivalent under JCT, NEC, or FIDIC. The mechanics differ around notice periods and valuation rules, but both adjust contracted scope, price, and time.
How Long Does Approval Usually Take?
The contract sets the deadlines, so there is no universal figure. Private clients with a single decision maker can turn a change around in days. Institutional and public owners route requests through several reviewers and often add surety or board approval above a stated threshold.
What Happens If Work Proceeds Without a Change Order?
The contractor has performed work with no contractual authorization and no agreed price. Payment then depends on proving the work was directed, which is difficult without written evidence. The remedy is to stop, document what was instructed and by whom, then issue a directive or change order.
Comments (0)
Back to Architecture and Design Blog