During the behind the scenes "Making of" documentary, it becomes clear that, the hotel interior set design not only uses the available official Sound Stage floor spaces, but also flow out to include the (dressed/disguised) "backstage" Elstree Studio buildings areas, such as studio corridors, dressing rooms, offices, etc. By coincidence, it appears that most of the Elstree Studios' Sound Stages and related studio buildings used for "The Shining" were later demolished in the notorious Brent Walker period, for what would become the site of the Tesco Supermarket, making this behind the scenes film, and "The Shining" itself, unintentional records of the Elstree Studios site prior to the demolition.
This documentary can be found on the 2-Disc Special Edition DVD of The Shining (1980), released in 2007.
Actor James Mason and his family visit the set, as he was nearby filming Murder by Decree. He is seen in his character's costume, which Vivian points out in her commentary track.