[5] Age 16, van den Ban told her mother that she wanted to study at Delft University of Technology and she became the first woman from the Netherlands to graduate as a civil engineer there.

[6] Van den Ban briefly taught mathematics at the Municipal hogere burgerschool (secondary school) in Haarlem in 1919.

She then held a position with Provincial Water Authority of North Holland as an urban planner for almost a quarter of a century.

Here, she revolutionised the development of planning by promoting the use of curvatures in the construction of streets and roads, rather than straight lines[8][9][10] and was involved in the creation of the Zuid-Kennemerland National Park initially suggested by Jac.

[11] She was on the board of Vereniging van vrouwen met hogere opleiding (VVAO) (Association for Women University Graduates) from 1931 to 1937 and was chairman when it was founded afd Haarlem in 1937.