Installation of new windows is an exciting process that may, in the hands of qualified professional installers, only take 2-3 days to complete. Moving your furniture and other items away from the windows and covering them to your satisfaction will help speed the process, though covering is optional, as window installation raises little dust.
Expect the installers to put down drop cloths for their work, and otherwise treat your belongings with respect. Part of the crew will be removing old windows, while the other part will be installing the new to keep the number of exposed openings to a minimum. In the case of extremely cold weather, professional installers may opt to work on just one window at a time, to minimize your heat loss.
Installing replacement windows can be much more complicated than putting in new ones. Settling may have occurred over the years leaving the window openings skewed. A high level of skill is needed to ensure that the replacement window will be squared up.
Wondering if you can save money by doing it yourself? Probably, but consider that replacement will include careful measuring, taking off the sash, prying off the jamb liners, removing the old window, insulating, installing the new, shimming (to level up), caulking, priming and painting. A conservative estimate puts this at a 4-6 hour job, with experience, while a professional crew may get 8-10 windows done in a day.
At the end of the working day, the pros should leave no window opening without either a new or old window in it. Even though there still may be some drafts if the final sealing is not complete, no boarded up windows, which might invite vandalism, should be left. Rooms should be left broom-clean.
Feeling comfortable around the installation crew is extremely important. Fortunately, Darryl and the whole Home Design team always get rave reviews for their professionalism, courtesy, and excellence of execution!