[1] In this capacity, he rebuilt Fort Crèvecoeur in Accra in 1839, which had been left in a ruinous state ever since Shirley's Gold Coast expedition of 1781.

As a private architect, he built several merchant houses on the Herenweg, nowadays Liverpool Street, in Elmina.

[2][3][4] During major Jan Verveer's campaign against Ahanta in June and July 1838, Varlet commanded a group of Euro-African volunteers.

Carel Hendrik Varlet followed in his father's footsteps and was appointed assistant on the Gold Coast in 1864.

He returned to the Netherlands after one-and-a-half years, however, and later settled as a merchant in Assinie on the French Gold Coast.