if the interior measures 81" how can the opening of the doorway be 84" , on the 7'x7' shed?

Hello, thank you for your inquiry. The interior width of the shed can be less than the exterior width due to the thickness of the shed's walls and framing. In the case of the Rubbermaid 7-ft x 7-ft Roughneck shed, the interior dimension measures 81 inches, while the door opening or exterior width is listed as about 84 inches. This difference occurs because the walls and structural components take up some space between the exterior and interior measurements. If you have any more questions, please reach out to us via our Contact Us form so we can help you further. We’re available Mon.-Fri. 9 am – 8 pm Eastern Time. Thank you! Rubbermaid Consumer Care