Change Orders 101: How Low Bids Become Expensive Projects

A low bid can feel like a win.

Until the change orders start.

If you’ve ever watched a “great price” turn into a frustrating, over-budget project, you’ve seen the pattern: the initial quote looks unbeatable, but it’s built on vague scope, missing assumptions, and plenty of room to charge extra later.

This post breaks down how the bait-and-switch works (sometimes intentionally, sometimes just through sloppy estimating) and how to protect yourself—whether you’re the buyer choosing a vendor or the contractor trying to sell the right way.

If you’re dealing with price-shopping right now, you’ll also want: How to Convey Your Value When the Lowest Bidder Is Too Good to Be True. And for the bigger-picture warning signs of price wars, read: The Race to the Bottom: Why Competing on Price Destroys Your Business (and Your Industry).

What a change order should be

A change order is supposed to be simple: the customer changes the scope, so the price and timeline change too.

Legitimate examples:

The owner adds new locations, devices, features, or rooms
Site conditions differ from what anyone could reasonably see (hidden damage, unsafe wiring, blocked conduit)
The schedule changes (night work, weekend work, accelerated timeline)

In other words, the project changed. The problem is that low bids often use change orders for something else.

How low bids become expensive projects (the mechanics)

When a quote is dramatically lower than the market, it’s usually not magic. It’s one (or more) of these tactics.

1) The scope is intentionally vague

The proposal sounds complete, but it’s written in a way that hides what’s missing.

Red-flag phrases:

“As needed”
“As required” (without defining required by whom)
“Includes standard materials.”
“Install equipment” (without quantities, models, or locations)
“Provide cabling” (without type, pathway, terminations, testing)

A vague scope is a blank check. It makes the bid look low and pushes the real pricing into “later.”

2) Allowances are used as a trap

Allowances aren’t automatically bad. They’re useful when details truly aren’t known.

But they’re also a common way to underprice the initial quote.

Examples:

“Includes $X for materials” (with no unit pricing)
“Includes Y hours of labor” (with no definition of what counts)
“Includes Z feet of cable” (with no plan or takeoff)

If the allowance is unrealistic, the change order is guaranteed.

3) Critical line items are excluded (quietly)

Some bids omit the parts of the job that make projects go smoothly—because those parts cost money.

Common omissions:

Permits, inspections, and code compliance work
Testing/commissioning and documented results
Labeling, as-builts, diagrams, and closeout packages
Project management and coordination
Warranty response and post-install support
Patch/repair of drywall, ceiling tiles, and firestopping
Disposal, cleanup, and site protection

So the customer thinks they’re comparing the same job.

They’re not.

4) The “change order factory” is baked into the process

Some companies run projects like this:

Win with a low number
Start fast
Hit the customer with “unforeseen” add-ons
Use schedule pressure to force approvals

Even when it’s not malicious, it’s a business model: profit is made on change orders, not on the original scope.

5) The timeline is weaponized

The cheapest bid often assumes the easiest schedule.

Then reality hits:

Access is limited
Work must happen after hours
Coordination takes longer
Other trades are in the way

If the contract doesn’t define schedule assumptions, the vendor can claim the delay is “on you,” and the acceleration is “extra.”

The real cost isn’t just money

Change orders don’t only increase the final invoice. They create:

Delays and rework
Decision fatigue (“approve this today or we stop work”)
Finger-pointing between trades
A project that never feels finished

That’s why the cheapest bid can become the most expensive project.

How to protect yourself (as the buyer)

You don’t need to become a technical expert. You just need to force scope clarity.

Ask these 7 questions before you sign

Can you list quantities and locations? (devices, drops, circuits, endpoints)
What’s excluded? (get it in writing)
What assumptions are you making? (access, hours, pathways, ceiling type, existing infrastructure)
What does “complete” mean? (testing, labeling, documentation, training)
How do you price change orders? (rates, markup, approval process)
What triggers a change order? (define it)
What’s your closeout process? (punch list, warranty, response time)

If a vendor can’t answer these clearly, you’re not buying a fixed price—you’re buying a starting price.

How to protect yourself (as the contractor selling the right way)

If you’re the professional bidder, you can win without being the cheapest—but you have to make your scope hard to compare.

Use “scope language” that prevents games

Add these sections to every proposal:

Scope of Work (detailed): quantities, locations, materials, standards
Assumptions: what you’re basing the price on
Exclusions: what is not included
Change Order Process: how changes are requested, priced, and approved
Acceptance Criteria: what “done” means (testing, documentation, sign-off)
Schedule & Access Requirements: hours, lead times, site readiness

This isn’t legal fluff—it’s how you protect the project.

Borrow this copy (and make it yours)

Assumptions (example):

“This proposal is based on normal business-hour access, clear pathways for cabling, and existing infrastructure being in a serviceable condition. If site conditions differ materially from these assumptions, we will notify the customer and provide a written change order for approval prior to proceeding.”

Change order definition (example):

“A change order applies only when the customer requests a modification to the agreed scope, or when concealed site conditions are discovered that could not reasonably be identified during the site walk. No additional work will be performed without written approval.”

Scope clarity line (example):

“Our pricing is built to avoid surprises. If you’re comparing bids, we’re happy to review scope parity to confirm you’re evaluating the same deliverables.”

How to talk about low bids without sounding bitter

Here’s a simple, calm way to frame it:

“Sometimes a low bid is just a different scope. The fastest way to know is to compare assumptions, exclusions, and what ‘complete’ includes—testing, documentation, permits, and warranty support. We price the full job so you don’t get nickeled-and-dimed later.”

Professional. Direct. No trash talk.