Seattle contractor Rich Gaspar spares no expense when it comes to protecting the jobsite. On big jobs, Gaspar Construction crews lay bubble wrap covered with Masonite on wood floors and install plastic walls. They wrap balusters and balustrades in rolls of 1/2-inch plastic foam and add carpet scraps for additional protection. Company crews also set up two or three box fans to suck dust out of the house. Trade contractors who fail to turn on the fans are responsible for whatever dust gets into the house, up to and including the cost of a whole-house cleaning.

Site protection is not a priority for all companies, as Rehoboth Beach, Del., contractor Patty McDaniel was reminded not long ago. A day after her crew finished putting up crown molding, McDaniel received a call from the client who was "stunned" because they'd laid down drop cloths and vacuumed. A previous contractor did good work but left a mess.

Drop cloths, runways, walls of plastic sheeting, and other protective procedures "lower the blood pressure," McDaniel says. When contractors neglect site protection, "the client feels it's his job to watch you every second. And if anything's wrong at the end, it's your fault. If you've done your due diligence, they're not going to have an opening to blame something on you that may not have been there before."

Gaspar estimates that, depending on the scope of work, the white-glove treatment he gives his clients takes "two guys, for a day." He lists costs under "Mobilization and Demobilization of the Jobsite" on his estimates. The company owns ZipWalls and rents them to the client as a job cost. That occasionally raises eyebrows. (One client expressed shock at the $2,200 price tag for site cleaning and daily broom cleaning.) But, Gaspar says, "anything you can do to put the real cost of the job out there and mark it up" is good business.

McDaniel includes site protection costs under "Supervision, Utility, and Cleaning." "I don't have a separate line item for it," she says. "To us, it's more useful in building client relationships than as a profit item."