Complex sentence: Due to the large number of pupils attending the new school an extension was built in 2009, it included an assembly hall, kitchen, toilets, learning support room, computer room, a classroom, staff room and an office.
Split into simpler sentences: Due to the large number of pupils attending the new school an extension was built in 2009. It included an assembly hall, kitchen, toilets, learning support room, computer room, a classroom, staff room and an office.