Heusaff was born on 2 September in the city of Brest in the Brittany region of France. His grandfather, Erwin Heusaff, had been born in Swansea in Wales, and Heusaff grew up without a father in his childhood, leading him to be taunted by his schoolmates for having an unmarried mother. He graduated from the University of Western Brittany in 1976 and the Gurteen College, located in Ireland, in 1986. He served in the Direction Centrale de la Police aux Frontières from 1976 to 1978 and in the French Land Army from 1981 to 1983. Heusaff led a Cadet chapter in Vannes from 1978 to 1979. After leaving the military he became the deputy chairman of a collective farm in 1983 and in 1986. He was promoted to the post of director of the Brittany state farm and construction materials plant in the Snowdon