Sadit meetup? I think half of the active users here are the same person or a small few, so it would be a small meeting.

Hang a sheet of thick plastic over the doorway of the room you are working on. Home Depot sells a zipper that you tape to this sheet of plastic down the middle. Unzip and cut a slit in the plastic with a razor knife. You now have a dust barrier you can seal up easily each time you need to walk through. It is sold in the paint section near the plastic drop cloths.