In 1855 Roberts applied to erect a corrugated iron house, described in the rate books as three rooms and a kitchen. In August 1857 Lloyd Tayler, architect, called for "tenders for additions to the dwelling house of Mr. William George Roberts, at East Melbourne". This resulted in a brick cottage behind the iron house. In 1879 Mrs. Roberts commissioned builders Marshall & Son of 14 Gore Street, Fitzroy to build a brick house which replaced the corrugated iron house, and in effect became an extension of the brick cottage. An advertisement in the Argus from 1858 reads,

LADIES' INSTITUTE, Sydenham House, Hotham-street, East Melbourne, conducted by Mr. and Mrs. William George Roberts; established 1855 - VACANCIES for DAY-PUPILS and two BOARDERS Students may attend [..illeg..] dancing, French, Latin, or [..illeg..] Professor Delplanque

A more specific entry in 1866 advertises, 'Superior education, Music, drawing, languages, elocution. Private lessons.'

William George Roberts (born Germany c.1814) died in 1876 but his wife, Margaret Roberts (born c.1823) remained in charge of the school until its closure in 1900. Her three unmarried daughters, Edith Annie (born c.1847), Lillian Margaret (born c.1850) and Nina Beatrice lived with her and no doubt assisted with the school. Mrs. Roberts died in 1901 leaving the house, then valued at £1,100 to her daughters. The family continued to occupy the house until the mid 1930s.

William and Margaret Roberts and their two oldest daughters arrived in Melbourne in 1854 aboard the Sussex. William was a member of the vestry committee of Trinity Church, East Melbourne