Positioning edge loops with precision I'm pretty new to Blender I'm trying to design a room with widows at specific locations along the wall. The method I'm using is to add edge loops and then delete the faces on the inside and outside of the wall. 

I'm having a really hard time positioning the edge loops to the exact location that's needed. So for example I know edge loop 1 is x inches from the left edge and I know the next edge loop should be 41" from that one etc. 

Sliding edge loops to accomplish this seems painful and I'm wondering if there's a better way to do this.
The factor of the Edge Loop is a value between -1 and 1. Assuming you know the total length of the wall (w), and (x) is the distance from the corner,  you can use this formula :

factor = 1-x/w*2


To enter the formula, press the = while using the loopcut tool, then type your values.

But this is tedious, cause the total length will be reduced by each cut. It would be much easier to extrude faces starting from the left, because extrude allows to specify distance values.