Are the Kara no Kyoukai movies based off chapters from one book or seperate books? In the Kara no Kyoukai, each movie is referred to as a Chapter so I've been wondering if they all comes from a single book or separate books and when they say Chapter they are referring to the movie collection (like how some anime series use Chapter # instead of Episode #)
From the Type-Moon Wiki the chapters of the light novel are:


Chapter 1 – Overlooking the Scenery (俯瞰風景, Fukan Fuukei) Thanatos
Chapter 2 – Murder Speculation (Part 1) (殺人考察(前), Satsujin Kousatsu (Zen)) …and nothing heart.
Chapter 3 – Remaining Sense of Pain (痛覚残留, Tsuukaku Zanryuu) ever cry, never life.
Chapter 4 – The Hollow Shrine (伽藍の洞, Garan no Dou) garan-no-dou.
Intermission - Kirie/Fujino (境界式, Kyoukai Shiki)
Chapter 5 – Paradox Spiral (矛盾螺旋, Mujun Rasen) Paradox Paradigm.
Chapter 6 – Oblivion Recorder (忘却録音, Boukyaku Rokuon) Fairy Tale.
Intermission - Lio (境界式, Kyoukai Shiki)
Chapter 7 – Murder Speculation (Part 2) (殺人考察(後), Satsujin Kousatsu (Go)) …not nothing heart.
Boundary of Emptiness (空の境界, Kara no Kyoukai)
Future Gospel (未来福音, Mirai Fukuin) recalled out summer
Final Record (終末録音, Shuumatsu Rokuon) the Garden of Oblivion 


And the animated films:


2007-12-01 (Japan, Part 1 - Fukan Fuukei) (same as Chapter 1 of novel)
2007-12-29 (Japan, Part 2 - Satsujin Kousatsu) (same as Chapter 2 of novel)
2008-01-26 (Japan, Part 3 - Tsuukaku Zanryuu) (same as Chapter 3 of novel)
2008-05-24 (Japan, Part 4 - Garan no Dou) (same as Chapter 4 of novel)
2008-08-16 (Japan, Part 5 - Mujun Rasen) (same as Chapter 5 of novel)
2008-12-20 (Japan, Part 6 - Boukyaku Rokuon) (same as Chapter 6 of novel)
2009-08-08 (Japan, Part 7 - Satsujin Kousatsu [conclusion]) (same as Chapter 7 of novel)


So the movies' chapters refer to the same chapters from the light novel.