Change Order Pricing: The Hidden Costs Contractors Miss

What Your Contract Says About Changes

Every standard construction contract includes a changes clause. Understanding what it says before you sign is critical, because once the contract is executed, the changes clause defines your rights and obligations when scope shifts.

AIA A201-2017, Article 7 defines three types of changes:

• Change Order (Section 7.2): A written agreement signed by owner, contractor, and architect that modifies the contract sum, contract time, or both. This is the gold standard: everyone agrees on the scope, cost, and time impact before the work proceeds.
• Construction Change Directive (Section 7.3): A written order signed by the owner and architect directing a change, even without the contractor's agreement on cost or time. The contractor must proceed with the work while the pricing is negotiated. This is common on fast-track projects where the owner cannot wait for pricing before starting changed work.
• Minor Change (Section 7.4): A written order by the architect for minor changes that do not affect the contract sum or time. These do not require the contractor's agreement, but they also cannot increase your cost.

ConsensusDocs 200, Article 8 uses a simpler framework: the owner issues a Change Order Request, the contractor prices it, and if both parties agree, it becomes a Change Order. If they disagree, the owner can issue a Work Directive (similar to AIA's Construction Change Directive), and the contractor must proceed while preserving the right to dispute the cost.

The critical takeaway: under both contract forms, you are required to proceed with changed work even if you disagree with the pricing. Your remedy is to document your costs contemporaneously and resolve the dispute later. Refusing to perform directed changes is a breach of contract.

Extended Overhead: The Most Underpriced Item

When a change order extends the project schedule, your general conditions costs keep running. The superintendent is still on site. The trailer, temporary power, portable toilets, and dumpsters are still being rented. Your project manager is still managing. Insurance premiums continue. These costs are real, quantifiable, and almost always underpriced or omitted entirely from change order proposals.

Calculating extended general conditions:

Daily General Conditions Rate = Total Project General Conditions / Original Contract Duration (working days)

If your general conditions budget is $180,000 for a 240-working-day project, your daily rate is $750/day. A change order that extends the schedule by 15 working days costs $11,250 in extended general conditions alone, before you price a single hour of labor or dollar of material for the changed work itself.

Home office overhead (Eichleay formula): In addition to field general conditions, change-order delays can entitle you to recovery of home office overhead. The Eichleay formula, recognized by federal boards of contract appeals and many state courts, calculates the daily home office overhead rate allocable to the delayed project:

Step 1: Allocable OH = (Contract Billings / Total Billings During Period) × Total Home Office OH
Step 2: Daily Rate = Allocable OH / Original Contract Days
Step 3: Extended OH = Daily Rate × Delay Days

The Eichleay formula applies most clearly to government contracts and to delays that are "suspensions" of work (your crew is on standby, unable to take other work). On private work, your entitlement to home office overhead depends on the contract language and the jurisdiction.

Schedule Impact Documentation

Every change order that affects the critical path entitles you to a time extension. The challenge is proving that the change actually impacted the critical path, not just that you did extra work.

Contemporaneous schedule updates are your best evidence. Update your CPM schedule monthly at minimum. When a change order is issued, insert the changed work activities into the schedule and run the forward pass. If the project completion date shifts, you have a documented critical path impact.

Types of delay:

• Critical delay: Extends the project completion date. Entitles you to a time extension and potentially extended overhead recovery.
• Non-critical delay: Consumes float on a non-critical path. Does not extend completion, but may reduce your scheduling flexibility for future work.
• Concurrent delay: Both the owner-caused change and a contractor-caused delay affect the critical path simultaneously. Most jurisdictions apportion responsibility, but the rules vary. Document everything and let the schedule analysis sort it out.

What to document for each change:

• Date the change was directed or discovered
• Activities affected (by schedule activity ID)
• Duration of added or modified activities
• Logic ties to predecessor and successor activities
• Resource impacts (crew size, equipment)
• Updated schedule showing the time impact

If you do not maintain an updated CPM schedule, proving critical path impact becomes an opinion fight between your expert and the owner's expert. That is expensive and unpredictable. A contemporaneous schedule is a fact.

Remobilization, Ripple Effects, and Rework

Remobilization: If a change order requires you to bring a crew back to a completed area, the mobilization cost is real. A crew that was already on site working in that area could have done the extra work at marginal cost. A crew that has to be pulled from another task, relocated to a different part of the building, and set up again costs significantly more. Price remobilization as a separate line item: travel time, tool transport, re-setup of staging or scaffolding, and lost productivity on the work they were pulled from.

Productivity loss (ripple effect): Studies by the Mechanical Contractors Association of America (MCAA) and the National Electrical Contractors Association (NECA) have documented that change orders reduce labor productivity on unchanged work by 5-30%, depending on the volume and timing of changes. This happens because changes disrupt work sequences, create congestion, require re-planning, and force crews to work out of normal sequence.

The MCAA publication "Change Orders, Productivity, Overtime" provides labor productivity loss factors based on the percentage of project work affected by changes:

Rework and demolition: If completed work must be torn out and redone due to owner-directed changes, price the demolition, disposal, and replacement as separate items. Do not absorb rework costs into the changed work pricing. The owner directed the change that made the original work incorrect, and they are responsible for the cost of undoing it.

How to Document Change Orders for Maximum Recovery

The quality of your documentation determines the quality of your recovery. Poorly documented change orders get negotiated down. Well-documented change orders get paid.

At the time of the change:

• Photograph existing conditions before any changed work begins
• Log the date, time, and person who directed the change
• Issue written notice within the contract-required timeframe (typically 7-21 days under AIA and ConsensusDocs)
• If the change was verbal, follow up with a written confirmation ("Per our conversation on [date], you directed us to...")

During the changed work:

• Track labor hours daily on a separate cost code for each change order
• Keep material invoices and delivery tickets segregated
• Photograph the work in progress at key milestones
• Document equipment usage (type, hours, dates)
• Record any impacts to other ongoing work

In the change order proposal:

• Reference the specific contract section authorizing the change (e.g., "Per AIA A201 Section 7.3.3")
• Include detailed labor breakdowns by trade and task
• Attach material quotes or invoices
• Show equipment rates from published rate guides (Blue Book, FEMA Schedule) or your internal rate schedule
• Itemize overhead and profit as separate line items
• Include the schedule impact analysis
• Attach photographs

The proposal should tell a complete story: what changed, why it changed, what it cost, and how long it took. A reviewer should be able to approve it without needing to call you for additional information.

Markup and Profit on Change Order Work

Most contracts specify the allowable markup on change order work. Common contractual markups:

If your contract does not specify a markup, AIA A201 Section 7.3.3.3 allows "reasonable" overhead and profit. What is reasonable depends on the scope and complexity of the change. A straightforward material substitution warrants less markup than a complex re-sequencing of work in an occupied building.

On subcontractor change orders, you are entitled to markup on top of the subcontractor's price. This is your compensation for managing, coordinating, and taking responsibility for the sub's changed work. The sub applies their own markup (typically 15-20%), and you add your prime contractor markup (typically 5-10%) on top of the sub's total.

Watch for contract language that limits the "tier" of markups. Some federal and state contracts prohibit sub-sub markups or limit the total number of markup tiers to prevent cost inflation on multi-tier subcontracted work.