3 Mistakes Boston Homeowners Make Before Hiring a Contractor

Avoid these common missteps before your next renovation — they cost more than you think.

Hiring a contractor is one of the biggest decisions a homeowner makes. Get it right and you end up with a project that comes in on time, on budget, and exactly as promised. Get it wrong and you're dealing with delays, unexpected costs, and work that has to be redone.

Most of the costly mistakes homeowners make don't happen during the project — they happen before it starts. Here are the three we see most often in Greater Boston, and what to do instead.

Mistake #1 — Choosing the Lowest Bid Without Understanding Why It's Low

This is the most common mistake, and it's easy to understand why it happens. Renovation quotes vary wildly. When three contractors give you estimates and one comes in significantly lower than the others, it's tempting to take it at face value.

But a low bid isn't automatically a good deal. In most cases, it means something has been left out. Maybe the contractor hasn't accounted for permit costs. Maybe they're planning to use lower-grade materials than the other bids. Maybe they've underestimated the labor involved and will come back later with change orders that close the gap — or worse, they'll cut corners to protect their margin.

The right way to evaluate bids isn't to compare the bottom-line number. It's to compare what's included. Ask each contractor to walk you through their estimate line by line. What materials are specified? Are permits included? What's their process when unexpected conditions come up during demo? The answers will tell you far more than the number at the bottom of the page.

In Boston's contractor market, a bid that's significantly below the others almost always has a reason — and that reason rarely benefits the homeowner.

Mistake #2 — Not Verifying Licensing and Insurance Before Signing Anything

Massachusetts requires general contractors to hold a Construction Supervisor License issued by the state. Hiring an unlicensed contractor isn't just a risk to the quality of the work — it's a risk to your homeowner's insurance coverage, your ability to sell the home later, and your legal standing if something goes wrong.

Insurance matters just as much. A contractor working in your home without liability insurance and workers' compensation coverage means you could be held responsible if a worker is injured on your property.

Verifying both takes five minutes. Ask any contractor you're seriously considering for their license number and certificate of insurance. A legitimate contractor will hand these over without hesitation. You can verify a Massachusetts Construction Supervisor License directly through the state's online licensing lookup. If a contractor is evasive about either — move on.

At Tar Hill Corp, our license number is CS-104636 and we carry full liability insurance and workers' compensation on every project. We include this information proactively because we believe homeowners should always know who they're letting into their home.

Mistake #3 — Starting Without a Clear, Written Scope of Work

A verbal agreement is not a contract. A vague contract is almost as bad. One of the most common sources of disputes between homeowners and contractors is a disagreement about what was actually included in the project — and those disagreements are almost always the result of a scope of work that wasn't specific enough at the start.

Before any work begins, you should have a written contract that clearly specifies what is being done, what materials are being used (including brand, model, or grade where applicable), what the payment schedule is, what the timeline looks like, and how changes to the scope will be handled.

That last point — how changes are handled — is particularly important. Unexpected conditions come up on renovation projects, especially in Boston's older housing stock. When they do, the process for approving additional work and cost should be clearly defined in writing before the project starts, not negotiated mid-demo when you're already committed and have no leverage.

A contractor who pushes back on putting details in writing is a contractor worth walking away from.

What to Do Instead

Before signing with any contractor, run through this checklist:

Get at least three bids and compare them line by line — not just the total. Verify the license number through Massachusetts state licensing lookup. Ask for a certificate of insurance and confirm it covers both liability and workers' compensation. Read the contract carefully and make sure the scope, materials, timeline, and change order process are all spelled out in writing. Ask for references from recent projects similar to yours and actually call them.

None of this takes long. And it's far less painful than dealing with the consequences of skipping it.

If you're planning a renovation in Greater Boston and want to work with a licensed, insured contractor who puts everything in writing from day one, we'd love to hear about your project. Learn more about our renovation services or get in touch for a free estimate.