221B Baker Street is the fictional London residence of the detective Sherlock Holmes, created by author Arthur Conan Doyle. The address could indicate an upstairs apartment of a residential house on what was originally a Georgian terrace. The B of the address might, however, refer to the whole house. The street is considerably wider than is portrayed in some film versions of Holmes's adventures and is a substantial and busy north-south thoroughfare, which is at least as congested now as it would have been in Holmes's day.
The site of the house — had it ever existed (see below) — would have been at the north end of Baker Street on the west side, near Regent's Park and Baker Street tube station. This justifies the claim of the Sherlock Holmes Museum that they occupy the real location of 221b Baker Street.
The 'real' 221B Baker Street
The street number 221B has never been assigned to any property in Baker Street. In Sherlock Holmes's time, street numbers in Baker Street only went up to No 100, which was presumably why Conan Doyle chose the fictional number.
The part now encompassing 221 Baker Street was known in Doyle's lifetime as Upper Baker Street, and in the first manuscript, Doyle put Holmes's home in "Upper Baker Street", indicating that if he had a house in mind it would have been in the section north of Marylebone Road, near Regent's Park. When street numbers were re-allocated in the 1930s, the block of odd numbers from 219 to 229 was assigned to an Art Deco building known as Abbey House, constructed in 1932 for the Abbey Road Building Society (subsequently the Abbey National), which the company occupied until 2002.
Almost immediately, the building society started receiving correspondence to Sherlock Holmes from all over the world, in such volumes that it appointed a permanent "secretary to Sherlock Holmes" to deal with it. In 1999, Abbey National sponsored the creation of a bronze statue of Sherlock Holmes that now stands at the entrance to Baker Street tube station.
Holmes scholars have had a number of theories as to the "real" address. With much of Baker Street devastated during the blitz, little trace is left of the original buildings, and most of them are post-war, except those in what was known as Upper Baker Street.
The Sherlock Holmes Museum
The Sherlock Holmes Museum is housed in an 1815 house similar to the fictional 221B. Its official address is 239 Baker Street. Opened in 1990, it displays exhibits in period rooms, wax figures and Holmes memorabilia. Both Abbey House and the Sherlock Holmes Museum declared themselves to be the "real" 221B: the outcome of a dispute between the two in 1994, when the museum applied unsuccessfully for permission to renumber itself 221. Today both have a claim: Abbey House is where 221B "could have been" and the museum is where Sherlock Holmes's post is delivered.
According to the published stories, "221b Baker Street" was a suite of rooms on the first floor of a lodging house above a flight of 17 steps. The main study overlooked Baker Street, and Holmes's bedroom was adjacent to this room at the rear of the house, with Dr Watson's bedroom being on the 2nd floor, overlooking a rear yard that had a plane tree in it.
The Museum adopted the street number '221b' from the time it opened to the public, but it faced significant bureaucratic hurdles in getting official acceptance of its claims to being the real '221b Baker Street', as described in the stories.
In order to physically display the number "221b" on its front door without falling foul of planning regulations, it had to register a company called "221b Ltd", because companies do not require planning permission to display a company name on the entrance to a building.
This ruse did not go down well with local planning officers, particularly Westminster City Council's Street Naming and Numbering Officer.
The Museum also discovered that the local council's street naming and numbering powers did not extend to interior apartments, only to the external parts of buildings, and therefore "221b Baker Street" was de facto firmly established in Baker Street after 100 years, despite the numerous bureaucratic hurdles to its creation.
After the closure of Abbey House, the museum took on the duties of answering all of Holmes's post and reports that it still receives letters – up to 50 a week – inquiring after Holmes or his services. The US News & World Report of 19 January 1987 quoted one reply as saying: "Mr Holmes thanks you for your letter. At the moment he is in retirement in Sussex, keeping bees." In The Adventure of the Second Stain and The Adventure of the Lion's Mane Holmes' retirement is described as such.