Graduated from Ecole Boulle and ENSAD, Henri Quill (1928-2020), settled on the island of Formentera (Balearic Islands) in 1972. There, he built for a mainly international clientele 30 houses of great consistency and is part of both principles derived from vernacular know-how and in those of the great masters of modernity. He says to pursue the local architecture, in particular by making extensive use of the Catalan vault, reducing openings to protect against the heat, covering the exterior walls with a lime plaster and sand. A pioneer of ecological housing, he will build a dozen self-sufficient houses. With the architects Felix Julbe and Raimon Torres, he collaborated on the regulatory plan and planning work on the island of Formentera from 1973 to 1976. Combining plans, period photographs and contemporary shots, this book allows this architect and his houses to be given their rightful place in the history of 20th century architecture. Text in English and French.