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Your Home: The Guide

Tips for building an addition to your home

Want an extra bedroom or a larger kitchen? If you’re considering expanding, here’s what you must know.

Illustration by James Steinberg

EVEN BEFORE NATE AND KATIE Maxfield signed their purchase and sale agreement in 2008, they knew the Cape they’d found in Wakefield wasn’t living up to its potential despite its ideal location. “It was in an area where it’s hard to find affordable homes,” says Nate, a designer at Verizon and a freelance game developer for phones and tablets. “We knew it was a good neighborhood to get into. Tightknit, lots of young families, lots of renovations going on.” But at just 1,400 square feet, the four-bedroom house was too small. “We knew we needed more room.”

The solution? Not just one but two additions — one already done, one still to come.


“In the fall of 2010,” says Nate, “we expanded off the side of the house, putting a living room downstairs and a bedroom upstairs. That let us turn the smallest bedroom into a playroom and the old master into a spare bedroom-slash-office.” In the next five to 10 years, they plan to add a dormer to the back roof to open up enough floor space to create an upstairs bath and additional closet space. The finished product, Nate says, will give them exactly what they want, where they want it, for a price they can afford. “We bought the house for $350,000,” he says, “and figured we’d spend $50,000 on each addition. We looked at homes nearby in the $450,000 price range, and there wasn’t anything that compared to it.”

In a bedroom community with smaller properties, like Wakefield, an addition can increase the value of your house, says Gerald Barrett, an agent with Christopher J. Barrett Realtors in the town. “I don’t think you’d get 100 percent of your money back,” he says, “but maybe 75 percent, and your house won’t sit on the market for long.” Of course, an addition is not for someone who’s planning to leave any time soon. “It allows you to customize the house to what you want,” says Barrett, who opted for his own 1,500-square-foot addition several years ago. “It’s hard to put a price on personal enjoyment.”


Still, building an addition can seem like a daunting prospect — especially if you plan to do some of the work yourself or even act as your own general contractor, as Nate Maxfield did. Here, what you need to know to get started.

1. Assess Your True Needs

Amy Tangorra, a kitchen and bath designer and the co-owner of Our House design+build in Reading, says it’s often best to wait till you’ve been in the house at least a few months to decide what you want to do. “Sometimes the answers are obvious,” she says, “but other times it takes awhile to decide what is and is not working for you.”

For a kitchen remodel, for example, Tangorra might ask questions like: Do you entertain while preparing meals? Do you have kids sitting in here a lot? Does mail tend to pile up in the corner? Even if you think you know what you want, bringing in a consultant — “someone who has all those things on their radar,” she says — even for just an hour or two, can be money well spent. “It’s dangerous to go into a renovation not having explored all of those things,” Tangorra maintains.

“The day of giant additions has come and gone,” says Stephen Kasper, construction supervisor and co-owner of Our House and head of Galaxy Contracting in Reading — particularly with money tight and downsizing trendy. People are still interested in creating common space in the form of family rooms or adding first-floor master suites with retirement in mind, but many also opt just to bump out the kitchen a bit or perhaps even, as was the case for one client Kasper had in Melrose, add something as small as a 16-square-foot laundry room. “It’s easy to want to go overboard,” he says, “but keeping your needs in mind helps you keep costs down.”


Once you’ve settled on a vision and how much you want to spend, enlist the services of an architect. Even if you know exactly what you want and can sketch out a decent approximation, you’ll need someone who can do the drawings that must be filed with your local inspectional services department. Your architect will also know the zoning regulations of the town or city you live in, including setbacks (how far a structure must be from property lines and other features) and maximums for height and square footage. If what you’re looking for falls outside the regulations, you will have to change your plan or apply for a variance. “That can be a long process,” says Kasper. “In Boston, it can take almost a year.”

2. Decide Who Will Supervise

Many homeowners hire a general contractor to do everything from pulling the permits to overseeing the last coat of paint, while others opt to handle this supervisory role on their own. Hiring a general contractor, often referred to as a “GC,” will add 20 percent to 40 percent to the cost of the job but will greatly minimize your involvement. “If you do it yourself,” says Karla Coelho, owner of Coelho Contracting in Medford, “the difficult part is coordinating everybody. Everybody has a question for [you], so you basically have to be available for them all. It’s almost a full-time job.”


Some homeowners, however, enjoy the challenge of acting as their own general contractor or find the cost savings significant enough to warrant the work involved. Nate Maxfield did the general contracting on his first addition but had guidance along the way from friend Joe Marino, who owns Marino Construction in Chelmsford. “We were very budget-conscious,” says Maxfield. “There was probably a lot of stuff I should have had Joe do, but every penny counts.” As for subcontractors, Marino recommended a few to Maxfield, who then hired them himself, saving the cost of Marino’s supervision.

Time may be a consideration. “A subcontractor that throws off your schedule throws off everybody that follows,” says Kasper. “Also, the homeowner probably isn’t going to get the loyalty [that a general contractor would]. If the homeowner calls and says I need you here tomorrow, the subcontractor knows they’re only talking about one job, not 10.” But if there’s no rush, once the addition is weather-tight, it may not matter to you if weeks or months elapse between the rough electrical and the finish work.


Finally, if you decide to supervise the project, you’ll have to learn not only about the process but also about the materials: What grade and type of insulation should you buy? Double- or triple-pane windows? Vinyl, cedar, or another type of siding? What kind of switches do you want — sensor, childproof, dimmer? At each step on the way, do as much research online as possible, and use the resources of your local big-box stores — they offer classes in everything from tiling to replacing a vanity, and sometimes their employees are former contractors themselves and very knowledgeable. Buy a book or two on how to build an addition, because, as Maxfield points out, you can never be prepared enough. “I had no idea what I was getting into,” he says. “No idea.”

3. Start the Hiring Process

Next on your to-do list is interviewing contractors and getting bids on the job. Since prices for an addition, depending on the finishes and work involved, can range from $130 a square foot to $225 and up, multiple estimates are crucial. Make sure any contactors you hire — whether you’re getting someone to oversee the job or finding subcontractors on your own — have up-to-date licenses and certifications, liability insurance, and workers’ comp “before they even step into the house, dig anything, touch anything,” says Coelho. Also check their reviews on sites like Angie’s List, which can tell you if workers disappeared mid-job or didn’t return phone calls.

Begin the hiring phase as soon as possible, because chances are the folks you select won’t be able to start right away. “You’ve got to give the contractor enough time to put it in the schedule,” says Marino.

4. Understand the Progression of the Work

If you’re acting as your own general contractor, knowing the order in which jobs must be done is crucial. It’s less so if you hire a general contractor, but still helpful, giving you a handle on whether the work is moving as it should.

Once the building permits are secured, work can begin. If you’re doing an addition that expands your house into the yard rather than, say, putting a second floor on a ranch house or building over the attached garage, the first step is having the foundation slab poured or basement excavated. A full basement adds quite a bit to the final cost, since it entails not only digging a large hole and carting away the debris but also additional plumbing, electrical, insulation, and waterproofing. But if extra space is what you need, it can be worth it. Maxfield recalls that Marino suggested this route to create additional storage. “And thank God he did. We were able to take everything we were trying to hide everywhere else and put it into one area.”

Framing, installing windows and doors, and buttoning up the roof come next, and should be done relatively quickly. “If all goes well, it all takes about a week, with four guys,” Marino says, “to put new floor joists, new walls, new ceiling joists, new roof rafters, and to roof it and install the windows.”

Once the room is weather-tight, “rough” — that is, inside-the-wall — plumbing and electrical work are done, insulation is installed, and the abutting wall of your existing home is torn down. Finally, blueboard or drywall is installed and plastered or finished, flooring goes down, the walls are painted, the trim is nailed in place, and final touches such as light fixtures go in.

Building inspectors have to sign off at many stages along the way, and you can always expect delays and surprises. What if the wall you plan to tear down turns out to have a crucial pipe inside it? Which brings us to . . .

 5. Plan for the Chaos

Doing an addition can be “extraordinarily disruptive,” says Tangorra, even though good contractors try to contain the upheaval as much as possible by setting up Porta-Pottys, sealing off abutting windows to minimize dust, and making sure to clean up the work area before they leave for the day.

“Try in advance to get organized,” says Kasper. He had one client who could never find her keys after work on the addition began, because she was used to hanging them on a hook by the back door that had temporarily disappeared. “We just set up another spot where she put her stuff,” he says, “and she came in the front door instead of the back door.” For extra insurance, he attached a lockbox at the front that held an extra set of keys.

Kitchen additions can be particularly unsettling because they inevitably involve the concurrent tearing apart of the existing kitchen. “With a kitchen,” Tangorra says, “the first thing I tell people is try to set up another area with a microwave, a fridge. A lot of families do renovations in the summertime because they can barbecue and stay out of the house more.” You might find you have to do dishes in the bathroom sink or tub. That’s no fun if the bathroom is next to the kitchen, but imagine if part of the reason for the addition is that the first floor lacks a bathroom. Schlepping dishes to the second-floor bath for a month can fray even the mellowest family member’s nerves.

That’s why experts recommend getting everything else as organized as possible if you plan to stay in the house while the work is being done. Put temporary shelving somewhere easily reachable to hold everyday items that might no longer have a home, such as canned goods, toiletries, umbrellas, and sporting gear, and clear away some of the clutter by renting a Pods container, which can be left in your yard for access or hauled away for storage while the addition is under construction.

The Maxfields’ first addition wasn’t terribly disruptive, since most of the work was done before the wall was opened to join the new rooms to the old, but their second addition might prove a little more troublesome, because building a dormer means first tearing down existing walls to access the work space. The family has the option of moving in with Katie’s parents for a time or simply cramming into the downstairs, putting both children in one room and making better use of the partially finished basement.


But they think the result will be worth a few months of inconvenience. “We love the house and get compliments on it all the time,” says Nate. “Everyone in the neighborhood who walks by says how nice the first addition looks, and it gave us the extra space we needed. And unless one of my games takes off and becomes the next Angry Birds, we’re going to be here for the long haul.”



What can you expect to pay for an addition that is midrange in quality on a home in Boston — and how much of that can you get back when you sell? These estimates come from the Remodeling 2011-12 Cost vs. Value Report (

> Bathroom Addition

Job Cost: $49,628

Resale Value: $25,110

> Family Room Addition

Job Cost: $99,695

Resale Value: $60,474

> Master Suite Addition

Job Cost: $128,776

Resale Value: $78,476

> Garage Addition

Job Cost: $66,707

Resale Value: $43,515

Elizabeth Gehrman is a frequent contributor to the Globe Magazine. Send comments to