City of San Mateo Law Library
City of San Mateo Municipal Code.


No owner may place, maintain or allow to remain thereon any number other than such number as herein required, or permit any such building or structure having an entrance from a public street to remain unnumbered.

(a) Entrances from streets to buildings must be numbered at the expense of the owner. All residential buildings shall display a street number in a prominent location on the street side of the building in such a position that the number is readily visible from approaching emergency vehicles. The numerals shall be not less than four (4) inches in height for single family and residential buildings and not less than six (6) inches in height for all other buildings. Numerals, letters or other identifications shall be used to identify individual residential units, offices or other spaces within a building and shall not be less than four (4) inches in height. All numerals or other identification shall be of contrasting color to the background surface to which they are attached and shall be illuminated during the hours of darkness when located at the exterior of the building.