Dust Containment Doorways. Before the project starts, always designate one doorway as the entry and exit to the work area. To seal up the other doorways, we use 6-mil poly and masking or blue tape. For doorways that open onto other rooms or hallways, we seal both sides. For the designated entry doorway, we use a two-layer plastic system. On each side of the jamb we secure one sheet of plastic that's 12 in., bigger than the doorway on all four sides. (We use masking or blue tape, or a staple gun if the jamb isn't finished.) Leaving the sheet on the dusty work side of the door intact as a single sheet, we slit the outside sheet down the center. These plastic skirts will help keep airborne dust from traveling. Another option I've seen work well is to install a temporary dust door. These plastic doors (around $20) open and close with zippers. Protective Products is the leading maker of them and other clever dust-control systems. Depressurize the room. Whoever is in charge of dust control should pick a window at the far end of the work area and mount a window fan there, blowing out. We seal around the fan and window frame with 6-mil poly, then we tape the plastic to the sides of the fan to create a good seal. Weather permitting, we run the fan all day long. This draws air into the work area and keeps dust from drifting to other areas of the house. Adjust HVAC system. If ducts are part of your heating-and-cooling system, make sure it doesn't run during construction, if possible, or divert air away from the work area. We cover any registers in the work area with kraft paper and tape. (I tell homeowners who have to run the system to replace filters weekly during the project.) We also remove all window air-conditioning units from the work area—they easily get clogged with dust. Work outside. Once the job is under way, the main source of dust comes from cutting wood. I have my carpenters cut outside whenever possible, but for wood cuts that must be made indoors, I ask that they attach dust-collecting vacuums to their power saws. The same goes for sanders, especially those used by drywall contractors. It's a good idea to follow this example if you're doing the work yourself. Sweep up and vacuum. Whether it's a big job or a small one, at the end of each day I have my crew sweep up; twice a week we thoroughly vacuum the work area. Before anyone uses a shop vacuum, we clean it out and brush off the filters. I've also found that lightly misting the filter with water makes it more effective at trapping fine dust. We always purge the vacuum by running it outside the house for a minute before bringing it inside. A dirty vacuum started "cold" indoors will throw off lots of its own dust. Get a cleaning service. No matter how carefully you and your contractor follow my advice, the job site will get dusty and some dust will find its way outside the work areas. All my remodeling contracts include a fee for a cleaning service. Typically I write in six hours of cleaning to be done at the end of the project. If you want or need more, add that in during the initial contract review or hire a cleaning service on your own.