Dust barriers like zipwall allow you to close off the remodeling area from the rest of the house and still have access. Find zipwall on Amazon.com

In addition to the zip wall, we use a small fan ejecting air out of the dust area going out side of the building. This makes a vacuum (negative pressure) in the dusty area and will insure that the tented area does not release dust through the small cracks into the home.

We do both zip walls and a fan. We also cut off all HVAC systems in the house while we are working.