<P> The office and warehouse of the Scranton branch office were sets on the production company's office in Van Nuys, California, although a real office was used in the show's first season . For episodes in season two and beyond, scenes set in the parking lot made use of the exterior of the production company's office building . Since the stage set had no windows, writer Jennifer Celotta's office was dressed to look like Michael Scott's when the script called for him or someone else to look out the window into the parking lot . In the second and subsequent seasons, the office interiors and exteriors are at a different location in Van Nuys . </P> <P> Some viewers have presumed that the Pennsylvania Paper & Supply Company's tower, a downtown Scranton landmark which appears in video footage shot by cast member John Krasinski for the show's opening credits, is the Dunder Mifflin office . The real company, which also sells paper and office supplies, has welcomed the exposure (and increase in business) and has a ground - floor showroom where it sells both its products and T - shirts with the tower . It plans to add a Dunder Mifflin logo to the circular insets near the top of the tower . Mifflin Avenue ends adjacent to the Penn Paper & Supply building . </P> <P> The success of the show has led to the sale of actual products with the Dunder Mifflin logo as souvenirs . NBC sells branded T - shirts, mugs, calendars and other items at its website, as well as in the NBC store located in New York City . In 2006, the website 80stees.com ranked Dunder Mifflin second only to Duff Beer from The Simpsons as the best fictional brand . </P> <P> At the first annual The Office convention in Scranton in 2007, fans who had paid for reserved seating at an "uncommon stockholders meeting" in the Mall at Steamtown received an annual report and complimentary ream of paper . A nearby elevator shaft is also decorated with the company logo . While the Scranton branch's address, 1725 Slough Avenue, does not actually exist (the street name was invented as a tribute to the original British version of the show, set in Slough, near London), the company logo can be seen two places in the city's downtown section outside the mall: on one of the pedestrian overpasses along Lackawanna Avenue, and a lamppost banner in front of City Hall . </P>

Where is the building used in the office