Is it permissible to take a loan from the bank to complete building a house and start a business project, given the deteriorating financial conditions and insufficient salary, with no job or capital in the home country?

If the loan is interest-based (usurious), it is not permissible to take it, because usury is among the most severe prohibitions. It is not permissible to engage in it except in a dire necessity, which is when a person reaches a point where if they do not consume what is forbidden, they will perish or be close to perishing. Owning a home is not a necessity as long as a person can find shelter, even if by renting. Taking an interest-based loan with the intention of not repaying it is a greater sin, as it combines usury with the intention of destroying wealth.