He attended the Delft University of Technology. After receiving his Engineer's degree Nassuth began working as an urban planner in the municipality of Amsterdam.
In 1962 Nassuth became projectmanager of a team which was planning the Bijlmermeer. When planning the Bijlmermeer, Nassuth was inspired by the CIAM, a prewar group of architects and town planners who stressed the importance of light, ventilation and space.
Nassuth remained involved in the planning of the Bijlmermeer until his retirement in 1981.