What SoEzzy is saying is that he built his just like mine.......Or I built mine just like his, but I got PICS. HA!!!!!
I used the charcoal grate out of my wsm so it measures 15 1/2" across and 10 1/2" high. I also gave myself about 3" of clearance.
Here it is with a full 12 lb bag of KF Comp.