Cardew, a civil engineer and licensed surveyor, was in charge of all the surveys for the development of the sewerage scheme in and around Sydney between 1883 to 1886 and then entered into private practice at 163 King Street, Sydney. Cardew undertook surveying in Hornsby in 1886, Bowral in 1886 and 1897, Leichhardt in 1892, Blacktown, Redfern, Croydon and Homebush in 1893, Stockton in 1894, Manly in 1885, Coogee and Waverly in 1886, Eveleigh in 1886, Annandale in 1887, Newtown in 1888, Moss Vale in 1899, Mosman in 1900, Neutral Bay in 1900 and 1904, Petersham in 1901, Cabarita in 1904, and Rose Bay in 1904 and 1907.