Complex sentence: Small Heath school has 2 bulidngs in which students study (the other building is situated on Muntz Street) the bulidings are also called upper and lower school (the Waverley Road building being called lower school).
Split into simpler sentences: Small Heath school has two buildings in which students study (the other is situated on Muntz Street). The buildings are also called upper and lower school (the Waverley Road building being called lower school).