A door is a hole in a wall that has to hold the wall up.

The job behind the photograph.

Any new opening means a header, and a header means load. Cutting a patio slider into an exterior wall takes a beam sized for what the roof above is doing, posts at each end carried down to bearing, and temporary shoring while the swap happens. Done properly you never think about it again.

Setting the unit is its own discipline. Square, plumb, shimmed at the hinge points, and flashed so water that gets behind the trim, and it will, has somewhere to go that is not the wall cavity. A slider that drags after 2 winters was almost always set out of square on day one.

Then the part that decides how it looks: casing and base scribed to walls that are not flat, mitres that stay closed, reveals held consistent around the opening, and paint or stain that matches what is already in the room. Trim is where a remodel either reads as finished or reads as nearly finished.