Buying the wrong window or door because you measured the opening incorrectly is likely to be a costly mistake. Buying a second window to replace it is just the beginning. You've got to send a crew back to the job again, and you will see payment delayed by 30 to 60 days.

Because they recognize the added costs, successful contractors put systems in place to avoid mismeasurements.

“First, we don't use the salesman's measurements at all,” says Brad Pompilli, president of Tri State Home Improvement, Branford, Conn. Instead, the company relies on an expediter who takes another complete set of measurements and compares them with the first.

At Weather Tight Corp., Franklin, Wis., they start by taking two sets of measurements. “We do a confirmation with a completely different person from the one who does the ordering,” says Todd Schulz, vice president. “We figure that if the same person does the confirmation, they are simply going to review their own mistakes and pass them through.”

The surveyor's measurements are “the bible,” at Seamless Siding Management, Randolph, N.J., says president Gerald Damora. But if the salesman's and surveyor's measurements are “off by more than 2 inches, we will go back to the house a second time,” he says. “That's policy.”

Recovery Mode Still, mistakes do happen. That's when dealers switch to recovery mode. “You have a choice when you are at the property,” Schulz says. “You can ask the homeowner if you can make an alteration in the opening to accept the window.” He has to pay the subcontractor more and often give the homeowner a $50 or $100 incentive, but he's not stuck with the window, Schulz says.

Damora has a “bone yard” of windows that is shared among a network of 28 dealers selling the same brand. Pompilli sells a few to contractors and others through a statewide classified advertising specialty newspaper. But “if they sit there for a while, we throw them away.” Schulz tries to sell them to people building new construction, where the window sizes may be flexible, and makes them available to employees and subcontractors, too.

“We try to get rid of them that way. All we're trying to do at that point is recover the cost of the product,” Schulz says. “It takes time, but normally we get rid of those windows somehow.”

Preventive Measures Work Mismeasurements are a serious mistake. All agree prevention is the best medicine. Damora and Pompilli both report less than 1% mismeasured windows annually. “We have more windows sitting in the warehouse because people didn't understand what a particular style looked like than we do because of measuring mistakes,” Pompilli says.