A change order is a written amendment to your original construction contract that documents a change in scope, cost, or schedule. It's signed by both you and your contractor before the additional work begins — and it's how legitimate contractors handle anything that falls outside the original agreement.
Change orders get a bad reputation, but they're not inherently a scam or a sign of a bad contractor. Some are unavoidable. Others are entirely predictable — and with the right preparation, you can minimize both the number and the size of the ones you face.
What Triggers a Change Order?
Anything that changes the original agreed scope of work can generate a change order. In our experience, they fall into three categories:
- Unforeseen conditions — problems discovered after demo begins: rot behind a shower wall, outdated knob-and-tube wiring, undersized structural headers, mold behind drywall. These are genuinely unknowable until the walls come open.
- Owner-driven changes — you decide mid-project that you want a different tile, an extra recessed light, or a layout tweak. Completely legitimate, but anything that wasn't in the original contract is a change order.
- Design gaps — plans or specifications that didn't cover every detail. The more thoroughly your project is documented before construction, the less room there is for ambiguity — and ambiguity is where change orders breed.
How Change Orders Are Priced
Every contractor prices change orders differently, and this is worth discussing before you sign your contract — not after you're three weeks into demolition.
Common pricing methods
- Time and materials (T&M) — actual labor hours plus material costs, often with a contractor markup for overhead and profit. Transparent, but harder to budget in advance.
- Fixed-price per change — the contractor quotes a lump sum for the additional work before you approve it. Easier to evaluate; gives you a clear number to say yes or no to.
- Percentage markup on cost — the contractor adds a set percentage on top of their actual costs. Common on larger commercial projects; less common on residential renovations.
Ask your contractor which method they use before signing the contract. A contractor who can't tell you — or is vague about it — is not set up to run a clean job.
What a Change Order Should Include (Don't Sign Without These)
A legitimate change order is a short, written document. It doesn't need to be complicated, but it needs to cover the basics:
- A clear description of the additional or modified work
- The agreed price (or T&M rate cap if it's not fixed)
- Any impact on the project schedule — days added, if applicable
- Signatures from both you and the contractor before work begins
- A running change-order number so you can track the total across the project
Do not let a contractor do additional work based on a verbal conversation and a handshake. 'We'll sort it out at the end' is how projects turn into disputes. Every change, no matter how small it seems, should be documented in writing.
How to Reduce Change Orders Before Your Project Starts
The best change-order strategy is prevention. Here's what actually moves the needle:
Make your selections early
Tile, fixtures, hardware, appliances, countertops — select these before construction begins, not during. When selections aren't finalized, contractors use allowances (placeholder budgets). If your actual selections cost more than the allowance, the difference becomes a change order. Lock in your choices early and you close that gap.
Invest in thorough pre-construction documentation
Detailed plans, specifications, and a comprehensive scope-of-work document are the best insurance against mid-project surprises. The more clearly the contract describes the finished product, the less room there is for 'I thought that was included' conversations.
Build a contingency into your budget
We tell every client the same thing: budget a contingency on top of the contract price. For a renovation in an older home — especially one where walls are being opened — 10–15% is reasonable. For newer construction or light cosmetic work, 5–10% may be enough. This isn't pessimism; it's how experienced renovators plan.
Ask about unforeseen-conditions clauses up front
Before signing, ask your contractor: 'What happens if you open a wall and find something unexpected?' A contractor who has thought through this — and can explain their process clearly — is better prepared than one who shrugs. You want a contractor who will call you before doing additional work, not present you with a bill afterward.
A Note on Massachusetts Contracts
In Massachusetts, any home improvement contract over $1,000 must be in writing under the Home Improvement Contractor (HIC) program — and change orders are an extension of that contract. The Massachusetts Office of Consumer Affairs and Business Regulation maintains the HIC registration database, which you can use to verify your contractor is properly registered before signing anything. You can find it at mass.gov/hic.
A written change order is not just good practice — on a registered home improvement project in Massachusetts, it's the standard you should insist on. If a contractor resists putting changes in writing, that resistance is information.
The Right Mindset Going In
Some change orders are unavoidable, especially in older homes where you genuinely can't know what's behind the walls until you look. The goal isn't to eliminate them entirely — it's to make sure every single one is documented, agreed upon, and signed before the work happens.
In our experience, the projects that go sideways financially aren't the ones that had change orders — they're the ones that had undocumented changes. The paper trail protects both sides. A contractor who pushes for written change orders is one who runs a professional operation.