DIY or hire a contractor for your home renovation? Here’s how to decide.

I have overseen many successful renovations, but I also know what it’s like to have a project turn into a total disaster. When my husband and I bought our apartment 20-plus years ago, it needed a gut renovation. I was pregnant, working full time and totally naive, and I hired a contractor without fully vetting him.

Almost a year into the job, our contractor went bankrupt and left before fully installing kitchen cabinets or finishing our bathroom.

I don’t want anyone to have a similar experience. Here’s advice from two professionals on determining whether you need a contractor and how to find one.

Before you can assess whether you need a professional contractor to oversee your project — including hiring all tradespeople and coordinating the timeline — you should develop a project plan, says Michael Grey, a senior project manager for Structure Works Construction in Millbrook, N.Y. Include as much information as possible about the design.

“Depending on the size and complexity of the project, this may include professionally developed construction drawings, or a list of paint colors and sheens for a small painting job, or something in between,” Grey says. “But no matter the scope, the plan must adequately describe the project and each of its various components.”

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Ultimately, your choice to take on a project versus hiring a general contractor comes down to your comfort level, knowledge and experience, as well as the size, nature and complexity of the project. To manage a project well, you need to feel comfortable consulting with all of the tradespeople, subcontractors and consultants.

If you decide to manage by yourself, Grey says, “be wary of carpenters that paint and painters that do trim carpentry, and never allow an unlicensed electrician or plumber to work in your home. Though there are certainly multi-skilled tradespeople available, use extra caution and verify their qualifications.

References from friends are a great place to start, says Renée deVignier Biery, a construction manager and interior designer based in Wilmington. Don’t stop there, though. You need to do serious research about the recommended professionals.

Never hire anyone without a face-to-face meeting, Grey says. It’s important to have good communication right out of the gate. If that is missing, consider hiring someone else.

Both Biery and Grey also insist that you go in person to see the contractor's work and ensure it's similar in scope to your own. Also make sure you are comfortable with their contract and the billing process, and verify that they are properly insured and licensed, and that they can meet your schedule.

Read every page of a contract and always ask about words or phrases you don’t understand, Biery says. Also ask what is not in your contract.

“No one ever asks that,” she says. “People get overwhelmed when they see a 40-page contract, and they assume everything is in it.”

An example, she says, is “scope creep,” which is when a homeowner adds little jobs here and there and doesn’t expect to pay for them.

“I often see clients ask a painter to touch up a different room from where they are working just because the client thinks it’s not a big deal, the painter is there, and the paint can is already open,” she says. “They don’t understand that means extra labor and time, so it changes the scope of the project.”

And remember that, when you sign off on a contract and bid, you become an active team member — not just a client hiring a service provider. “You will have to make decisions all along the way,” Biery says.

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Allowances are the dollar amounts that a contractor assigns to a given line item in a bid. Of course, it behooves a contractor to include the least-expensive option in a bid, because it makes the bottom line more palatable.

For example, if you say you want white subway tile for your bathroom, the contractor can assign a fee of $2 per square foot. But if you select tile that is $7 per square foot, that is a material difference in cost. Over the course of an entire project, those sliding numbers can add up, and suddenly, you can find yourself paying much more than you expected.

Research is key to avoiding this, Biery says. Before you begin a project, find out which fixtures, tiles, lighting and other materials you like. “Just go to build.com and put everything you think you want in a cart, and look at the bottom line,” she says. “You will have a very accurate idea of the cost, and when you go to bid out the job, contractors will be able to give you a more accurate estimate.”

The contractor will usually provide a payment schedule that’s based on the length of the job. Generally, there is an initial payment to secure the job, then monthly or quarterly payments, with a final payment due once the job is complete. For a smaller job, there might be only two payments: one at the beginning and one at the end. Never pay the full amount up front because you want to have some cushion to protect yourself in case something goes wrong.

Biery says not to try to negotiate overall costs. "If you do your research and due diligence and you have checked on all of the references, you should know that you are working with a reputable firm. Negotiating means there is fat to trim, and there should be no fat."

Beware of unrealistic expectations based on what you see on television, Biery says.

“Everyone watches HGTV and thinks they can do it themselves, but unfortunately, viewers aren’t fully educated on what happens behind the scenes,” she says. “Problems are not solved between commercial breaks.”