I feel something is "brand new" when it hasn't been used - ie for goods it means straight out of the box. For a hotel I suppose I would say it hasn't had any guests yet - as of the time of booking.

Being more generous I would say hasn't seen a complete year yet, ie less than 12 months.

For "recently renovated" - think that could mean anything.... If the hotel is 100 years old, then "recent" could be as much as 10 years... I'd suggest 2 or 3 would be a more reasonable maximum.

I wonder if its time to rename "New" York?