36 Bannerman Road

Maria Jackson and, later, Rani Chandra lived in a house at 36 Bannerman Road — or, according to some accounts, number 12 — in Ealing near Sarah Jane Smith, who lived at number 13. (TV: The Last Sontaran, The Day of the Clown)

Behind the scenes
Dialogue in The Last Sontaran and The Day of the Clown establishes the exact address as 36 Bannerman Road. In Invasion of the Bane and other episodes throughout the first series, though, the address of the house is clearly 12. It is possible, but unconfirmed, that 12 is the address of the real-life house used for filming in the first series, similar to the situation with Sarah Jane's house.