If you use Metro's southern Dupont station entrance on the regular, you'll need to find an alternative routine for most of 2012. The transit agency is closing the entire entrance to remove and replace the three escalators which move passengers from ground level to the mezzanine. The work was originally supposed to last one year, but Metro revised the timeline to 10 months, then 8 and one half months. The northern entrance at 20th and Q will remain open. 20th and Q has escalators as well as an elevator. There is no exact date for the closure, but it is planned to begin sometime in February.
This job is so big, Metro decided to bid the work out to a Swiss company rather than waiting to hire and train the dozens of additional workers required. The price tag is estimated at $12 million. According to Metro, the current escalators were custom built by a British company, which is no longer in the business of producing or maintaining escalators. That made sourcing parts and labor for repair extremely difficult and costly. With the re-installation of new escalators, it's hoped that the monies and labor spent on future maintenance will be kept to a minimum.
As for the 8.5 month estimate, I'm highly dubious. Let's come back to this on January 1, 2013 and see where the project stands. Until then, use the north entrance on 20th Street or walk south to the Farragut North station on Connecticut Ave and L Street NW.