"There is a library on the west side."
No, it is a different word with the same pronunciation. As a noun, it means "seat" e.g. 在座的人 (those present); as a measure word it is used for "immovable objects" e.g. 一座山 (mountain), 一座桥 (bridge).
I did a brief search and apparently it is a word that originates from 坐 or the 后起字 of 坐.