He was active primarily in Belgium, particularly in the regions around Brussels including Grimbergen and Ganshoren, where he found inspiration in the rural landscapes and village scenes. Fermeuse also traveled to Southern France, where he created numerous watercolors capturing the distinctive light and scenery of the region.
His works have been offered at auction multiple times since 1989, with his auction record reaching 539 USD for "Huile sur toile: Vaches près de l'abreuvoir" sold at Horta Auction House in 2001. Fermeuse continued painting until his death in 1963, leaving behind a body of work that reflects his deep connection to the Belgian countryside and its traditional way of life.