Remodeling the plumbing, HVAC, and interior surfaces doesn't necessarily mean a complete demolition. The interior panels are simply fastened to the concrete just like any new interiors would be, and I seriously doubt they have a hard fit between any plumbing and the existing concrete work as it goes through walls. If they had done that, every time the structure settled, moved slightly, or a difference in temperature caused expansion and contraction they would have had a plumbing leak. There are probably access holes through the walls and ceilings that could be used again. Since it is already a concrete structure with a steel re-rod reinforced core they could almost certainly add an additional floor, (maybe two). It would seem to me that gutting the interior but using the structure in place would be the quickest way to get the project done.
The drains do travel under the slab,,and have no vents ( can tell by the smell, and constant gurgling) ,, adding new rooms to the existing infastructure would be unwise, they most have something in the works .
Their venting for the drains may be clogged or insufficient but, trust me, DWV plumbing, especially on that scale cannot function without venting. The resulting vacuum would just stop up the whole works.
Sara 69 just posted on Facebook that those rooms don't have anything to do with the long-term construction... "3 rooms for premier ... To show the people and don't use the rooms in the hotel ...."
Contributing to that direction... I laid a lot of pipe last week so I definitely did my part towards the renovations/rebuilding.
I guess we will just monitor this thread for updates..I'm sure Steve will know when anything is official..will hold off booking anything until after the holidays...