It's interesting what happens when you put this in concrete terms (albeit a hypothetical example):
A 1928 golf course that originally played 6,500 yards; it had big and well contoured greens and wide playing corridors, and a minimal number of bunkers that were simply shaped but deep and penal - with fairway bunkers usually requiring a carry of about 220-230 yards.
Over time, the playing corridors got narrowed by rough and trees, the greens were flattened and then got smaller/shrunk as the collars got wider, and many bunkers were added both around the greens and in the fairways, while the original bunkers were filled in and moved further from the tees. No new tees, however, were ever added.
What's a restoration in this case? As my previous posts suggest, my view is that the word should be used the way it is commonly understood -- and that means that a restoration would a) bring the greens back to the original size and contour, b) bring back the fairways to their original width, including through the cutting down of trees c) get rid of the bunkers that had been added over the years, and bring the bunkers that were originally there back to their original depth and location, and d) would NOT add new back tees. Period. That's it. That is a "restoration" -- and everyone but architects and the committee members they woo know this.
And what would you have if you restored the course this way? A cool, lovely, playable, 6500 yard course that the vast majority of golfers today would find challenging and fun, in every way.
Now, If an architect and/or a committee member doesn't believe this, that's fine -- people can have honest disagreements and differing points of view. And if so, go right ahead -- add tees that stretch the course out to 7,000 yards and bring the "original" bunkers out to the 250 yard-carry mark etc etc. But then call it what it is: a "renovation".
Again, I don't understand this determination by industry types to use the "restoration" term even if it has to be bent all out of shape, nor do I understand the reluctance to use the term "renovation"; it is not a dirty word