In a career spanning six decades, he collaborated with architects including Le Corbusier, B. V. Doshi, Charles Correa, and Raj Rewal, and contributed to the structural design for more than 250 projects.
[4] He moved to Shimla and was assigned to the rehabilitation cell at the PWD which was tasked to build housing for displaced middle-class families.
He later collaborated with Indian architect and urban planner, Charles Correa, to build the Hindustan Lever pavilion at Pragati Maidan in New Delhi in 1961.
[3] The structure followed the idea of progression through a maze with space being enclosed by reinforced concrete cement sprayed under pressure to create random folds resembling a crumpled card.
[6][7] Raj worked with Pritzker prize winning architect B. V. Doshi in designing the Indian Institute of Management Bangalore and the Tagore Hall in Ahmedabad.
[9][10] He also worked with architect Shiv Nath Prasad on Akbar Hotel in Chanakyapuri, New Delhi,[11][12] as well as the Shri Ram Centre for Performing Arts.