Termite Damage Repair

[Kameeka Shirle]

I am analyzing a property that has extensive termite damage under the crawlspace and in the attic. Everything else was updated and renovated. The house is 100 years old and it is 781 Sq ft.  How do you repair termite damage to the foundation? About how much would it cost? What other considerations would I need to take into account (e.g. redoing the floor, new roof,  etc.)? Thanks!