Basement Windows in Brick Wall

I noticed, that very few people install windows directly into the wall. Most of the times there is a molding around the window. I guess the molding hides a wooden frame. Is there any reason to put frame inside of the brick opening and widndow inside of the frame? I would like to get biggest windows possible and the frame considerably reduces the size. Please advice.

By bobjohn | 09/20/2009 7:57 PM