10 Downing Street is the most famous house and consequently, has the most photographed door in the world. Known to the British as Number 10, it served as the official residence and workplace of the First Lord of Treasury from 1732 to 1905 before it became the home and office of the British Prime Minister. Painted in white on a shiny black door, the number 10 is the most famous of house number signs in the United Kingdom.
In 1766, Architect Kenton Couse redesigned the front door using six Georgian styled panels in black oak. In 1770, a lion head knocker, a brass letter plate with the inscription “First Lord of Treasury” and a door knob were installed vertically on the door.
In 1960, renovation works gave the front door a new look to the number 10, the design of which is kept until today. This renovation of the painted white numerals caused quite a stir because many have noticed that the number zero is slightly skewed to the left. Some theories state that the imperfect numeral is in reference to the first numeral zero that was badly affixed on the original door. However, Department of Typography and Graphic Communication’s Professor James Mosley theorizes that the zero is actually the capital letter O, as seen in the Roman’s Trajan Alphabet, a typeface that was used by the Ministry of Works in the 1960s.
In 1991, a mortar attack on Downing Street destroyed the black oak door. Since then, the black door was substituted with a blast proof steel door.
Today, the door of 10 Downing Street’s brass letter plate and door knob serve as decorative purposes. The door can only be opened from inside.