I'm kind of new to Blender and I ran into a problem. I am creating modular segments for a house. For some reason when I created the segment with a window in it, blender split the front face into 2 faces when I go into edit mode. Is there a way to rectify this? I created the segment using 2 cubes. One cube is the size of the wall, the other i used to cut out the window using a boolean modifier. I tried the "f" key and that didn't work for me.