Hi Mike This will depend, among other factors, of the level of precision you use. If you use Design --> unit of measure--> entire inches, the task will be easier I don't know how other programs work, but in Punch, if 2 walls are at 90°, and they are fused they show continuous surfaces in 3D, not a 45° joint. To set the angle, you can select the wall--> Edit--> Rotate--> write the angle. After you set the walls' shape and angles, you can select the walls with arrow with the # sign and write the exact dimensions of the walls Or you can try this (follow the explanation in the first image attached) 1 - Say you have a wall L=280" and you wish to add a bay windows with walls at 45° 2 - Break the walls using the wall break tool or add points--> set the desired dimensions--> say you wish to set the two walls with 60" at 45° 3 - In this case, I decided to move the 50" wall, so in the 60" wall of the left--> select the point closer to the 50" wall--> Edit--> Move--> Y= 60" (same dim of the length of the 60"wall) 4 - Repeat the procedure with the wall of the right--> Both walls have identical dims and are at 45° As you can see in the second image, in 3D, the surfaces are continuous Lets us know if you need additional help Patricia