During this period he executed perspective drawings of St. Vitus' Church in Hilversum and St. Bavo's Cathedral in Haarlem,[1] which so impressed Cuypers that he first promoted De Bazel to head draftsman and later his chief designer, overseeing the rest of the firm.

[1][2][3] Between 1897 and 1902 the duo taught courses alongside H. J. M. Walenkamp in the new Theosophical Vahânaloge they had founded in Amsterdam the previous year in drawing, art history and aesthetics; the institution operated until 1931.

Along with Hendrik Petrus Berlage, he pioneered the Dutch architectural rationalism that would become characteristic of national practice during and after the First World War.

This complex was founded by a wealthy student in response to an outbreak of typhus that had contaminated fresh milk that had been sold nationwide.

Similarly, in 1907, he designed a new district in the foothills of Semarang in the Dutch East Indies (now Indonesia) for his friend, the colonial pharmacist and activist Hendrik Tillema.

[4][2][3] Other works from this period include the building for the Nederlandse Heidemaatschappij (a Dutch environmental and infrastructure consulting and engineering firm, now called Arcadis) in Arnhem, built from 1912 to 1914, which was the first large-scale structure in the Netherlands to make use of reinforced concrete.

Well-known examples of this are the cradle he made for Princess Juliana of the Netherlands in 1909 and a Pulchikast that he designed for the occasion of the marriage of Queen Wilhelmina to Prince Hendrik in 1901.

[3][2] De Bazel also designed the stamps issued in honor of the centenary of the Kingdom of the Netherlands in 1913, which depicted the queen and her three predecessors.