Change Order Management: How to Control Scope and Cost During Construction

Changes are a normal part of construction.

Even well-planned projects can experience design revisions, client requests, unforeseen site conditions, material substitutions, additional quantities, or technical requirements that were not fully understood when the original contract was awarded.

The problem is not that changes happen.

The real problem begins when changes are executed without a controlled process.

Poor change order management in construction can lead to budget overruns, schedule delays, commercial disputes, duplicated work, and confusion over what is actually included in the contractor’s original scope.

For project owners and general contractors, effective change management is therefore not simply a commercial procedure. It is an important part of maintaining control over project scope, cost, schedule, and documentation throughout construction.

What Is a Change Order in Construction?

A construction change order is a formal modification to the original contract requirements.

It may change:

• Project scope
• Quantities
• Materials
• Drawings
• Specifications
• Contract price
• Construction schedule
• Method of execution

A change order can increase or decrease the contract value depending on the nature of the modification.

For example, if the project owner decides to add an additional room, the contractor may require additional civil, MEP, finishing, and possibly structural work.

That change needs to be technically defined, commercially evaluated, approved, and incorporated into the project documents.

Why Construction Change Orders Happen

There are many possible causes.

Client-Requested Changes

The project owner may decide to change:

• Room layouts
• Finishing materials
• Equipment
• Building functions
• External works
• MEP requirements

These changes can be simple or may affect several disciplines.

Design Revisions

Consultants may revise drawings due to:

• Coordination issues
• Technical improvements
• Updated requirements
• Authority comments
• Design development

Unforeseen Site Conditions

Actual site conditions may differ from available information.

Examples include:

• Underground utilities
• Unexpected soil conditions
• Existing structures
• Hidden services
• Rock excavation

Scope Gaps

A required activity may not have been clearly assigned in the original contract.

This can result in discussions over whether the work is included or should be treated as additional scope.

Material or Equipment Changes

A specified product may become unavailable, discontinued, delayed, or replaced by an approved alternative.

The replacement may have cost or installation implications.

Change Orders vs Variations

The terms change order and variation are often used interchangeably, although contract terminology can differ between projects.

In general, both refer to an authorized change to the original contracted scope.

The important issue is not the terminology.

The important issue is having a clear process for:

1. Identifying the change
2. Defining its technical impact
3. Evaluating the cost
4. Evaluating the schedule impact
5. Obtaining approval
6. Updating project documents
7. Executing the work

Skipping any of these stages can create future disputes.

1. Define the Change Clearly Before Pricing It

A contractor cannot accurately price an unclear instruction.

For example:

“Add more electrical outlets.”

This is not enough information.

The contractor may need to know:

• Number of outlets
• Locations
• Type
• Cable requirements
• Panel capacity
• Conduit route
• Wall finish impact
• Testing requirements

The clearer the technical definition, the more reliable the commercial quotation becomes.

Change order requests should therefore include drawings, sketches, specifications, quantities, or written technical instructions whenever possible.

2. Determine Whether the Work Is Actually Additional

Not every new instruction automatically creates additional cost.

Before approving a variation, the project team should compare the request against:

• Original drawings
• BOQ
• Specifications
• Scope of work
• Contractor proposal
• Tender clarifications
• Contract exclusions

The key question is:

Was this work already included in the original contractor responsibility?

If the answer is yes, the contractor may not be entitled to additional payment.

If the requirement genuinely changes the original scope, a change order may be justified.

This is why strong scope definition at contract award is so important.

3. Evaluate Direct Construction Costs

The contractor should provide a clear cost breakdown for additional work.

Direct costs may include:

• Labor
• Materials
• Equipment
• Subcontractors
• Transportation
• Testing
• Temporary works

For example, changing the size of a concrete foundation may increase:

• Excavation
• Formwork
• Reinforcement
• Concrete
• Backfilling

The commercial evaluation should consider the complete impact rather than only the most obvious item.

4. Consider Indirect Costs

Some changes create costs beyond the physical work itself.

These may include:

• Additional supervision
• Extended site facilities
• Equipment standby
• Remobilization
• Additional engineering
• Extended project management
• Temporary access changes

A relatively small design change may become expensive if it disrupts an established construction sequence.

This is especially important when the change occurs late in the project.

5. Assess the Schedule Impact

Every change order should be evaluated for its potential effect on time.

A change may require:

• New design approval
• Revised shop drawings
• Additional material approval
• New procurement
• Demolition of completed work
• Additional testing
• Reinspection

If the changed activity lies on the project’s critical path, the schedule impact can be significant.

The contractor should therefore identify whether the change:

• Has no schedule effect
• Can be absorbed within available float
• Delays a specific activity
• Changes the project completion date

Cost and schedule should be evaluated together.

6. Avoid Verbal Change Instructions

One of the most dangerous practices in construction is executing significant additional work based only on verbal instructions.

For example, someone may tell the site team:

“Go ahead now and we will handle the paperwork later.”

This creates risk for everyone.

Later disagreements may arise over:

• Who authorized the work
• What was requested
• Whether the work was additional
• What price was agreed
• Whether additional time was approved

Urgent situations sometimes require rapid action, but the instruction should still be documented through the approved project communication system.

7. Use Existing Contract Rates Where Appropriate

Some changes can be priced using existing BOQ unit rates.

For example, if the contract contains an agreed rate for reinforced concrete and an approved change increases the quantity, the same rate may be applicable depending on the contract conditions.

This can simplify commercial evaluation.

However, existing rates may not always be suitable.

A significant change in:

• Quantity
• Location
• Execution conditions
• Productivity
• Material requirements

may require a revised or new rate.

The contract should define how these situations are handled.

8. New Rates Should Be Supported

When no suitable contract rate exists, the contractor may propose a new rate.

The rate should ideally be supported by information such as:

• Supplier quotations
• Labor calculations
• Equipment costs
• Productivity assumptions
• Subcontractor prices
• Material quantities
• Applicable overheads

Transparent calculations make commercial review easier and reduce unnecessary negotiation.

9. Track Every Change in a Change Order Register

Large projects can generate many potential changes.

Without a register, it becomes difficult to know:

• Which changes are approved
• Which are under review
• Which have been rejected
• Which are awaiting pricing
• How much the project budget has changed

A typical change order register may contain:

• Change reference number
• Description
• Originator
• Date raised
• Related instruction
• Estimated cost
• Submitted cost
• Approved value
• Schedule impact
• Approval status
• Final authorization date

This provides project owners with a clearer view of commercial exposure.

10. Track Potential Changes Before They Become Approved Changes

Not every issue becomes a formal variation immediately.

Project teams may first identify a potential change.

For example, a consultant may be considering a revised equipment location but has not yet issued final instructions.

Tracking potential changes allows the owner to understand possible future cost exposure before final approval.

This can improve budget forecasting.

Instead of discovering at the end of the month that the project value has unexpectedly increased, the client can see developing commercial risks earlier.

Change Orders and Procurement

Changes can create serious procurement consequences.

Suppose a contractor has already ordered a pump based on the approved design.

A later change requires a larger capacity.

The impact may include:

• Cancellation fees
• New manufacturing time
• Price difference
• Shipping changes
• Storage of the original equipment
• Schedule delay

The cost of a change is therefore often affected by when it is issued.

Changes made during design are usually easier and cheaper to manage than changes issued after procurement or installation.

Change Orders and Completed Work

Late changes can create rework.

Imagine that walls, ceilings, and MEP services have already been completed.

The owner then requests a new piece of equipment requiring additional electrical and plumbing connections.

The work may require:

1. Removing finished surfaces
2. Installing additional services
3. Retesting systems
4. Repairing finishes
5. Reinspecting completed areas

The cost is much greater than it would have been if the requirement had been identified before finishing works.

Effective change management therefore includes understanding the construction stage when the change is introduced.

How Change Orders Affect Multiple Disciplines

Many changes are not limited to one contractor or one trade.

Consider moving a mechanical unit.

The change may affect:

• Structural support
• HVAC ducts
• Electrical connections
• Drainage
• Fire protection
• Ceiling layout
• Maintenance access

If only the mechanical cost is considered, the true financial impact will be underestimated.

General contractors should therefore evaluate changes across all affected disciplines before submitting or approving the final commercial value.

Change Orders in Industrial Construction

Industrial projects can be particularly sensitive to late scope changes.

Changes may involve:

• Production equipment
• Machinery foundations
• Utility connections
• Structural platforms
• Electrical loads
• Ventilation requirements
• Fire protection systems

A change to one production machine can affect both the building and several supporting systems.

For example, replacing equipment with a heavier model may require:

• Foundation redesign
• Additional reinforcement
• Revised power supply
• Modified cable routes
• Additional cooling
• Updated lifting plans

This is why technical coordination is essential before evaluating the full cost of industrial construction changes.

How Skilya Manages Change Across Integrated Construction Scopes

Skilya delivers projects through integrated capabilities that can include general contracting, civil construction, structural steel, MEP works, infrastructure, finishing, and other associated construction activities.

This integrated structure is particularly important when managing changes because a single client or design instruction may affect several scopes at the same time.

Rather than evaluating a modification only from one discipline’s perspective, Skilya can review how the change interacts with structural requirements, civil activities, MEP systems, steel fabrication, procurement, site sequencing, and finishing works.

For example, relocating industrial equipment may initially appear to be a mechanical change, but it can also require a revised foundation, electrical modifications, changes to utility connections, structural support, and adjustments to surrounding finishes.

Through its general contracting services, Skilya can coordinate these interfaces and assess the wider execution impact before the revised work proceeds.

This helps create clearer communication between project stakeholders, supports more accurate cost evaluation, reduces the risk of uncontrolled additional work, and allows approved changes to be integrated into the construction sequence more effectively.

For industrial and commercial projects in particular, coordinated change management can play an important role in protecting both the project budget and the overall delivery schedule.

Common Change Order Management Mistakes

Starting Work Before Approval

This creates commercial uncertainty and makes later negotiation more difficult.

Evaluating Only Material Cost

Changes can also affect labor, equipment, engineering, supervision, and schedule.

Ignoring Other Disciplines

A change to one system may create work for several others.

Poor Documentation

Without clear drawings and instructions, different parties may remember the change differently.

Waiting Until the End of the Project

Unresolved variation claims should not accumulate until project closeout.

Failing to Update Drawings

Approved changes should eventually be reflected in controlled construction and as-built documentation.

A Practical Change Order Workflow

A controlled process may follow this sequence:

1. Change identified

A new requirement or changed condition is discovered.

2. Technical scope defined

Drawings, sketches, or instructions explain the change.

3. Contractual review

The team determines whether the change falls inside or outside the original scope.

4. Cost evaluation

The contractor submits rates, quantities, and supporting calculations.

5. Schedule evaluation

Any time impact is identified.

6. Commercial negotiation

The parties clarify and agree the appropriate adjustment.

7. Formal approval

The authorized party issues approval.

8. Execution

The contractor performs the revised work.

9. Documentation update

Relevant drawings, registers, budgets, and project records are updated.

Following a consistent process creates a clearer audit trail throughout the project.

How Project Owners Can Reduce Change Order Costs

Not all changes can be eliminated, but several practices can reduce their frequency and impact.

Project owners should aim to:

• Complete design coordination before construction
• Define project requirements early
• Review the BOQ carefully
• Clarify scope interfaces
• Approve materials on time
• Make decisions before procurement
• Avoid late aesthetic changes
• Track potential variations
• Review cost and schedule together
• Use formal approval procedures

Early decision-making is one of the most effective ways to control construction changes.

Final Thoughts

Changes are part of construction, but uncontrolled changes do not have to be.

Strong change order management gives project owners and contractors a structured way to understand what has changed, why it changed, what it will cost, and whether it will affect the project schedule.

The most important principle is to avoid treating a change as only a price.

Every change should be evaluated as a combination of:

Scope + Cost + Time + Coordination + Documentation

When these five elements are managed together, project teams can implement necessary changes while maintaining much stronger control over the overall construction process.