The Castel Henriette, designed by Hector Guimard in 1899, was among the architect’s most imaginative residential commissions and an important expression of his emerging Art Nouveau style. Built in Sèvres, outside Paris, the villa featured an unconventional architectural composition in which asymmetrical forms, curving lines, and elaborate decorative details challenged traditional architectural conventions. Although the house was demolished in 1969, surviving architectural elements preserve evidence of Guimard’s remarkably integrated approach to design. The doors demonstrate his fascination with transforming conventional architectural forms into fluid, organic compositions. Their nested arches reinterpret traditional Gothic and Renaissance architectural motifs, while the inward-rolling scrolls of the oak cartouches echo the dynamic curves found throughout his furniture, interiors, and celebrated Paris Métro entrances. The collaboration with Georges Néret further illustrates Guimard’s commitment to the Gesamtkunstwerk, or total work of art, in which architecture, stained glass, woodwork, and metal fittings were conceived as complementary elements of a unified artistic vision.