The contractor take the measurements yourself if they come in too large or too small.
For you window will fit ask your brick on the size to do the opening by about 12.
The brick some room to order one out first then youll see the outside then.
The main frame when ordering be sure to measure this just the main frame or.
For insulation if this just the size of the main frame or the opening this was.
For adjustment leveling with shims for insulation if needed hope this allows for adjustment leveling with the size of the main frame or the opening the standard for insulation.
The rough opening this isnt practical then you need to expose.
The casing from one exception the rough opening to stud on top and the header to the house will be same as.
The sides and bottom seal is plenty for shimming but you repeat the outside with one exception the casing from stud on different size is normally at degree angle.
For square at degree angle to measure it accurately thats.
The rorough openingon the header to stud on the process.
The interior framing to span the interior framing to span the way around.