In 1841, Brunner's father put his son's name forward to the New Zealand Company, which was seeking prospective emigrants for its proposed settlement in the South Island of New Zealand. The company wanted to populate its new settlement with well educated young men of excellent character and with leadership potential. Furthermore, apprentice surveyors, at the time known as "improvers", were in particular demand and Brunner, aided by character references from his employer and other notable residents of Oxford, was duly selected to join the company. In addition to his work as an improver, he was to assist the settlement's principal surveyor, Frederick Tuckett.