Standards For Patio Design?

Need a hand please. I am trying to find if there is a standard for how a patio is attached to a house. I know that the top of the foundation must be 6" to 8" above grade, but if a patio is built up, can it go to the same level as an entry door? or above the sill plate? I just inspected a house that is having water entry problems where the patio meets the house, with the patio at the same level as the entry door and two full length windows, on a new construction, but cannot find and standard. Anyone have a reference?

A patio does not attach to a house. Are you referring to a deck?

Or are you asking about the patio abutment to a house?

A pic would be fantastic.

typicly, if the “patio” or deck is attached to the house, it is lag bolted to the sill plate, or cantaleavered (i probably spelled it wrong). in either case it requires ice/water barrier and flashing to guide water out about 6’’ or 8’’. don’t quote me, cuz i don’t know the actual numbers, but i know the method.