Is taking out a loan from a bank to purchase a house, with 5% interest over 20 years, considered usury (riba), knowing that there are no banks that lend without interest, and given the high cost of living and that "the strong believer is better than the weak believer"?

A loan stipulated with interest is usury, which is forbidden by Islamic law and is one of the major destructive sins. Usury is not permissible except in cases of dire necessity as defined by Islamic law. High living costs or the unavailability of interest-free loans do not make it permissible. The strength intended in the noble Hadith (definition) is the strength of the heart, resolve, and caution in matters of religion, which necessitates abandoning usury and dispensing with it by what Allah has made lawful.