Strictly speaking, you can keep buildings alive indefinitely by replacing their parts, like the ship of Theseus in 'fiction', or like really important Churches or other buildings of cultural significance. Unfortunately, this can't be done with humans, which is where we differ - for now!
@alexanderalexis I quite agree with your submission that building can be keep alive by just replacing their components part.Typical examples are acient palaces that still maintain their initial designed despite the age.Age has not nothing to do with how fast Buildings becomes obsolete.