Complex sentence: The building was originally the site of the Highams Manor, built in 1768 and the grounds of the school were designed by Humphrey Repton, who gives his name to one of the school's houses.
Split into simpler sentences: The building was originally the site of the Highams Manor, built in 1768. The grounds of the school were designed by Humphrey Repton, who gives his name to one of the school's houses.