You're halfway through a job when the homeowner decides they want the bathroom tile different, the cabinet run extended, or the electrical panel moved. 'It's just a small change,' they say. You agree, do the work, and when it's time to invoice, they act like it was part of the original bid. Now you're either eating the cost or having a painful conversation about extra charges. Neither is good.
A change order is a written agreement that says: this work was not in the original bid, here's what it costs, here's the timeline impact, and here's the signature that makes it binding. Without one, 'small changes' quietly add up to hundreds or thousands of dollars in lost profit. With one, you're protected, the customer knows what they're paying, and there's no argument at the end.
This guide covers what to put in a change order, how to price changes so you don't lose money, how to get it signed before you start work, and how to avoid scope creep. If you haven't already, read scope creep to understand how projects expand uncontrollably. A change order is how you stop it.
When You Need a Change Order
A change order is required when the customer asks for work that was not in the original estimate or contract. Examples:
- Moving a fixture, outlet, or door opening (not budgeted)
- Changing materials (granite instead of laminate, upgrade flooring)
- Adding or removing items (extra bathroom, removing a wall)
- Discovering hidden conditions (rot, asbestos, bad framing that needs replacement)
- Code upgrades required by inspection (not your fault, but needs a change order to document)
What's NOT a change order: work that was explicitly in the original scope, weather delays that are your responsibility, normal callbacks and warranty work, or mistakes you made that need to be fixed.
The Five Elements of a Change Order
A change order should include:
1. Description of the Change
Be specific. Not 'upgrade materials' — be exact: 'Upgrade kitchen backsplash from 12x12 ceramic tile to 3x6 subway tile, white gloss, with 1/8-inch grout lines. Remove existing tile and backerboard, install new backerboard, tile, and grout.'
The more detailed, the less room for misunderstanding. If the customer later claims they meant something different, you have documentation.
2. Cost Breakdown
Show the materials, labor, and profit. Don't just say '$500 for the change' — show the work:
- Materials: Subway tile, adhesive, grout, primer = $150
- Labor: 16 hours removal and installation at $65/hour = $1,040
- Overhead (15%): $178
- Profit margin (20%): $274
- Total: $1,642
When customers see the breakdown, they understand where the cost comes from. They may negotiate on materials or timeline, but they can't argue about something they don't see.
3. Timeline Impact
State whether the change delays the project and by how much. 'This change adds 3 days to the project timeline, pushing the completion date from April 15 to April 18.' If there's no impact, say so: 'No timeline impact; work completes on schedule.'
Timeline transparency prevents surprise delays and shows you've thought through the impact. If the customer is on a tight schedule, they can decide whether the change is worth the delay.
4. Authorization and Signature
Include a signature line: 'I authorize this change and agree to pay the amount above.' Without a signature, the change order is just a proposal. With one, it's a binding contract.
Get the signature before you start work. If you do the work first and ask for a signature later, they'll feel trapped and resentful. Get the signature upfront; it shows respect for their decision and protects both of you.
5. Reference to the Original Contract
Include: 'This change order is an addition to the original contract dated [date]. All other terms and conditions remain unchanged.' This clarifies that the change order doesn't replace or modify the original bid — it's an addition to it.
How to Price Change Orders Without Losing Money
Pricing a change order is trickier than pricing the original bid because you're usually mid-project and things are moving fast. Here are the rules to protect your margin:
Rule 1: Use Your Standard Labor Rate
Don't cut corners on labor cost. If your billing rate is $75/hour, use $75/hour. Don't drop it to $60/hour to make the change order cheaper. The work takes the same amount of time, and you deserve the same rate. The customer can always say no if it's too expensive.
Rule 2: Mark Up Materials
Price materials at wholesale or your cost plus a reasonable markup (15-25%). Don't use retail price; that's for retail customers. But also don't use net cost and hope you break even — you won't.
Rule 3: Include Overhead and Profit
Don't treat a change order like a discount. Include your overhead (10-15% of total cost) and profit margin (15-25%). A change order that doesn't include profit is a service — not a business move.
Rule 4: Add Contingency for Small Changes
For small changes (under 2 hours of work), add a 10-15% contingency to the labor estimate. These changes often take longer than expected because they're interruptions to the main flow of work. You're stopping what you're doing, setting up, doing the change, cleaning up, and getting back to the main task. That context-switching costs time.
Example Change Orders
Example 1: Moving an Electrical Outlet
Customer wants the kitchen outlet moved 3 feet to the right. Original outlet is rough-in; new location is behind where the fridge will go.
- Description: Remove existing outlet box and wire from current location. Run new wire 3 feet to new location. Install new outlet box and outlet. Patch drywall at old location.
- Materials: Wire (15 feet): $3 | Outlet box and outlet: $8 | Drywall patch materials: $5 | Total materials: $16
- Labor: Disconnect old outlet (0.25 hr), run new wire (0.5 hr), install new outlet (0.25 hr), patch drywall (0.5 hr), cleanup (0.25 hr) = 1.75 hours at $80/hour = $140
- Cost so far: $156
- Overhead (12%): $19
- Profit margin (20%): $35
- Change order total: $210
Example 2: Material Upgrade in Bathroom
Customer wants to upgrade from builder-grade tile to high-end marble tile in the bathroom.
- Description: Replace 8x10 ceramic floor tile (60 sq ft) with 12x24 marble tile. Remove existing tile and prep substrate. Install marble with thin-set and grout.
- Materials: Marble tile at $6/sq ft = $360 | Thin-set and grout: $60 | Total materials: $420
- Labor: Remove existing tile (2 hrs), prep (1 hr), install marble (4 hrs), grout (2 hrs) = 9 hours at $75/hour = $675
- Cost so far: $1,095
- Overhead (13%): $142
- Profit margin (20%): $280
- Change order total: $1,517
Getting the Signature
A change order is only binding if it's signed. Here's how to get it done properly:
Timing
Present the change order before you start the work. Verbally confirm with the customer, then hand them a printed change order to sign on the spot. 'Here's what this costs. Can I get your signature so I can get the materials and get started?'
Make It Easy to Sign
Print two copies. Customer keeps one, you keep one. Or email it and get a digital signature (DocuSign, email reply with 'I approve'). Whatever method you use, document it so you have proof the customer approved it.
If They Hesitate
If the customer says, 'Can you just do it and we'll figure out the price later?' — don't. Hold firm: 'I need to know the cost upfront so I can order materials and budget my time. Let me show you the breakdown.' If they still resist, the change may not be worth doing, or they're not serious about it.
Protecting Yourself from Scope Creep
A change order system prevents scope creep. When every change requires a new document and a customer signature, customers think twice before asking. They also understand the cost upfront, so there are no surprises. Read scope creep for more on how to prevent projects from expanding beyond your original bid.
Keep Change Orders Organized
For larger projects, change orders add up. You might have 3-5 change orders on a single job, each worth hundreds or thousands of dollars. Keep them organized: file them by date, reference them in your invoice, and total them up at the end so there's no confusion about what work was completed under what authorization.
Tools like BidFlow make it easy to generate consistent change orders with the same format and calculations so they're professional and clear. You can also track change orders alongside the original bid so you see at a glance what's been approved and what's still pending.
Bottom Line
A change order protects your profit and your relationship with the customer. It documents what's being changed, what it costs, and that the customer understands and approved it. Without one, 'small changes' silently erode your margin. With one, you're clear, professional, and protected. Write them, price them correctly, get them signed before you start the work, and file them away. That's how you stay profitable.