Complex sentence: For many years the school taught in its original three classrooms, however under the headship of Paul Gazzard the site has been expanded to include a fourth classroom, a hall and gymnasium, a library and a new reception area.
Split into simpler sentences: For many years the school taught in its original three classrooms. Under the headship of Paul Gazzard, however, the site has been expanded to include a fourth classroom, a hall and gymnasium, a library and a new reception area.