Many same extruded windows So I am looking for a way to extrude many similar windows in a wall. They should be exact size and stay on same distance from each other. How would you do that? Thanks.
As Lukasz-40sth said, you could use the Array modifier:


Create a plane, subdivide it.
Extrude your window.
Use 2 Array modifiers to repeat your object horizontally and vertically.
Work your window as much as you want until you're satisfied.
You can either keep or apply your modifiers.
If you want to apply, enable the Merge option of the modifier so that the adjacent vertices of your new object merge. If you didn't enable it, go in Edit mode, select all and Remove Doubles with W.