In 2004 it opened a preparatory department (known as Wetherby Prep, and intended to be a separate school) in a nearby building, allowing boys to stay on until the age of 13.

The school building is a white stucco double fronted Victorian house in the Italianate style typical of Notting Hill and Holland Park architecture, constructed in about 1850.

[1] In 2004, Wetherby expanded to open a prep division for boys aged 7 to 13, sited in Bryanston Square, London.

[2] Due to popular demand, Wetherby Senior School for boys aged 11 to 18 opened for its first intake in September 2015.

[3][4] It is located at the former premises of DLD College London on Marylebone Lane, a ten-minute walk away from the prep school.