Questions to Ask Before Adding On

Zoning and cost are some issues to consider before beginning this major home renovation

You've perused showrooms, flipped through home magazines, studied friends' houses—and perhaps even found design inspiration in your own dreams. You have a clear goal, a budget, and perhaps a scrapbook filled with clippings, brochures and back-of-an-envelope sketches. But you're not quite ready to start your addition project—until you ask yourself the following questions:

1) How would you design your house if you were building it new? "It's so hard to see past what's already there, like a bookcase or a doorway or wall," says New York City architect Dennis Wedlick. "So forget about your house. Imagine you're starting from scratch and create the ideal home." That liberates you to get really creative about what you want—and helps to prioritize your goals for the job. Then you can look for ways to turn your building into that dream house, through an addition, a remodeling project or a combination of both.

2) Will the addition add value to your home? Even if you have no plans to sell anytime soon, you (or your family) will sell someday—and you might also refinance or take out a home equity line of credit, for which you'll want the best possible appraisal of your home. So always consider the resale value of your project. It's not that you're going to turn a profit on your investment. So you might as well go into the job with realistic expectations about payback.

Because they're among the costliest home projects, addition jobs often return less than remodels. The Remodeling report pegs the following returns on additions: A two-story addition with a family room downstairs and master suite upstairs (65 percent); master-suite-only addition (63 percent); bathroom addition (53 percent); and sunroom addition (49 percent). To maximize your payback, add amenities that are highly sought after in your area. If your neighbors have master suites and you don't, then that's a good investment, says Omaha appraiser John Bredemeyer, past president of the Appraisal Institute, a standards setting organization. If nobody else on the block has one, your payback will be small.

3) Is there a lower-cost way to get what you want? The downturn in addition payback doesn't mean you shouldn't add on—assuming you're doing the work for your own enjoyment and intend to stay in the home for at least 5 years. But it does mean you might want to look for ways to cut the costs of your project. And the best way to do that is to look for ways to eliminate or minimize the need to add on—by using the attic or basement or by simply reconfiguring existing living space, says Eden Prairie, Minn., design-build contractor Mark Mackmiller.

4) Are there any zoning restrictions to consider? Most municipalities have rules about what you can build where—including when you're building an addition. For example, though local zoning laws vary, in a residential area, you're generally not allowed to build anything within 20 feet of the front of your property; 7.5 feet of either side, or 15 feet of the rear, according to Roy L. Fyffe, Building Official for Burnet, Texas, and spokesman for the American Association of Code Enforcement. There are also rules about how close you can get to wetlands and how much of your lot can be covered with impermeable materials (including both structures and paving)—as well as how tall buildings can be, which can limit additions that go up instead of out. Check with your local building department as you begin your project planning.

5) How will your addition tie into the house? Adding onto a home requires a bit of finesse to make it look like it belongs—while also taking advantage of all of the modern amenities available today, says Curt Schultz, a Realtor-architect-builder in Pasadena, Calif. You'll want to consider how the roofline connects to the house, how you'll compliment the style of the house, from the interior and exterior finish materials to the windows to the utilities and heating and cooling—and at the same time create a functional, modern space that will provide maximum benefit to your family without being overly taste or lifestyle specific. That's a tall order for the typical homeowner—or even many general contractors—to get right, so consider hiring an architect or designer to help create the best possible plan.

6) How much do you expect to spend on your addition? Since every house, every site, and every family’s wish list are different, the only way to get a realistic estimate for your particular project is to talk to local contractors. But as a general guideline, expect to spend anywhere from $100 to $200 (and up) per square foot.

Here are some average project costs for common addition jobs, from Remodeling magazine’s 2010-11 Cost vs. Value Report:

  • Bathroom Addition: $40,710
  • Upscale Bathroom Addition: $78,409
  • Family Room Addition: $85,740
  • Garage Addition: $60,608
  • Upscale Garage Addition: $90,053
  • Master Suite Addition: $108,090
  • Upscale Master Suite Addition: $232,062
  • Sunroom Addition: $75,224
  • Two Story Addition (master suite over family room): $165,243

And there are long-term costs to adding on as well. Increasing the size of your home means increasing your energy bills, especially for heating and cooling. Plus, you can expect your property taxes to climb, since tax assessments are based on the home’s vital statistics, starting with its square footage. Add amenities that weren’t there before, like an additional bathroom, a hot tub, or a fireplace, and your assessment will jump even higher.

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