Placing a Sweep inside window family.

[TJDRGAS]

I am learning families and decided to make my window frame a bit nicer with a Sweep, but I also wanted to parametrise how deep in the wall the window sits. I made my Sweep and tried to add a dimension with a parameter assigned, but the constraint was breaking. I Alligned the sweep to the Reference Plane and assigned a parameter to the sweep offset, that was basicly moving my Reference planes around.

Then I placed them without constraint with a parameter to the offset, and it worked in the family editor, but on the wall, there was some extra offset.

I finally noticed that Sweeps have a WORK PLANE, which earlier I didn't touch cos they were greyed out. Now it finally seems to work, but I still should ask some question. 

I stayed for now with the parameter assigned to the Sweep Profile Offset, but I noticed that the native Revit window families prefer adding a bunch of extra reference planes and adding parameters to them (via dimensions). Is it only a convention, or is there a solid reason why I should do it this way? 

I mean, it took me many tries before I finally understood how to incorporate Sweef into a window family, so I am not quite sure this iteration is error-resistant.

[mrtwelve2020]

This isn't a big problem; it can be solved with more practice and experimentation.

[TJDRGAS]

Not a big problem, and practise is needed with everything, but it was troublesome, and I wrote it more for people who may be on one of the earlier steps to help find the answer.

   To me, it was a big surprise to find that in the exterior view, following what I did with extrusions, I constrained the sweep path using dimensions with an assigned parameter or simply aligning lines to the reference planes, But when I go to the Left view, non ot it works, and there is all new way to constrain the same object in just this other direction. Just Did not see that coming. I'm used to 3Ds Max, Blender, sKetchup, where all dimensions are the same. Arrey works in all directions. 
Parametrisation is making the whole concept of operating in 3D completely different.