Let’s take a collective victory lap that this conversation is happening. For all of the angst and argumentative discourse we share on this site, be encouraged that golf architecture has jumped into the popular psyche of golf. Blame/credit this site for fueling the fire, and recognize the likes of Andy at Friedegg for sharing it with a wider audience. Public recognition and branding associated with golf architecture has improved golf, and raised the quality of a golf development script that previously worked to wedge a par 3 between 30 houses and a cul-de-sac. Golf Course Architects, both dead and alive, are now the brands that drive founders, members, developers, real estate value.
I agree with the decades of previous posts that work to declare that "restoration" is driven by provenance. EG: Photos, Plans, Aerials. The restoration should seek to "Restore" the course in a manner defined by the originating architect. You don't put Home Depot or Pella windows on a Frank Lloyd Wright House. You wouldn't replace a revetted Scottish bunker with a Florida gator pond. That said, it is reasonable and realistic to make room for interpretation as in many cases, a pure feature-for-future restoration is not possible based on sold off land, zoning, safety etc.
A significant departure from “Provenance” would deem that project a "renovation". A gaggle of new bunkers, radical departure from the original routing, architectural style, relocated, rebuilt, heavily altered greens, fairways, features and the like. This could arguably include the "Stimp Curse" where folks soften original greens to be able to run at 12-14, originally built to run at Stimps of 8-10. All of this could arguably move a project out of the restoration column, and into a renovation.
We crossed over based on a natural disaster:
1: We "restored" an overgrown Ross. No major alterations other than some performed decades earlier which include alteration of 3 holes were arguably “renovations”, but we had 15 holes and Greens originally routed by Ross, as such, we were a majority restored course. We made accommodations for an increasingly malevolent flood plain, but the Ross footprint remained. Ross would have likely made the same drainage and elevation tweaks had he returned. We also added bunkers never completed by Ross. Some placements were questionable and there was room for contention, but our intent was Ross and we did what we could with the info we had... which was thin.
2: A storm destroyed 70% of the course that was routed through groves of trees. Part of the routing devolved into NLE
3: Prichard returned to channel "What would Ross Do" for over 40% of what was originally routed by Ross through tree groves, that no longer existed.
4: Result: We are no longer a "Restoration". It is a "Renovation." We enjoyed our time as a “restoration” but no longer retain the "Provenance" given entire groves of trees were wiped from the earth. Hundreds of century aged specimen trees are not feasibly replaceable.
Summary: A project that departs significantly from the “Provenance” of the period recognized as the peak iteration of that course's existence is not a "Restoration".