Simplify the following text for a Grade 7 native English-speaking person.
Original: Through the employment of the pointed arch , walls could become less massive and window openings could be larger and grouped more closely together , so architects could achieve a more open , airy and graceful building .
Simplified: By using the pointed arch , walls could become less massive and window openings could be larger and grouped more closely together . This gave a more open , airy and graceful building .