Is money earned from renting out a house built without a government permit unlawful (haram), and how should one deal with a father who spends from it?

Building permits fall under the purview of the ولي الأمر (ruler/authority) to regulate construction, oversee urban development, and prevent transgressions. People are obligated to abide by them due to the public interest they serve and the harm they prevent. If the father overstepped these laws, he is sinful, and it is not permissible for him to revert to such actions. However, this does not prohibit benefiting from the said building or its rent. Therefore, it is permissible for you to benefit from the building's rent and consume from it, as it is not considered illicit money.