Five years ago, Criterium Engineers, a Portland, Maine, construction consulting firm, identified improper window installations as the No. 1 problem area reported by its 70 field offices from nearly 20,000 homes inspected nationally. And today? Company president Alan Mooney says the issues remain ... and are probably worse.

With an average of 19 in-wall windows per 2,300-square-foot house, there's a lot of potential for problems such as moisture infiltration, thermal loss, and expensive callbacks. And that potential for trouble too often is fulfilled on the job site, the product of a combination of old habits, a high turnover rate, language and literacy barriers, and conflicts of interest (e.g., framers get paid for speed, not precision).

Manufacturers and prevailing building codes have worked hard to make proper installation a clear-cut process. In addition to manufacturing completely assembled products, some suppliers also ship compatible components to help make installation easier and better.

Mooney also sees signs manufacturers may soon require (and provide training for) certified installers for their products and inspect installations before they'll activate a product warranty. "If that can be effectively administered and monitored, it will improve installation issues tremendously," he says.

Dealers can help by becoming a consultant to pro customers. Dealers can host training sessions given by manufacturers, trade associations, or code officials. They also should consider creating a construction services division that certifies crews to properly install its window brands.

–Rich Binsacca is a contributing editor to ProSales.