Is Hajj obligatory for someone who bought a house in installments and finished paying all of them, but the house requires extensive finishing work that would cost a large amount of money, or should they wait until the house is fully prepared?

If a man resides in a dwelling that suffices him and his family, Hajj is obligatory upon him first, as he is capable (of performing it), and he can complete his house later. Hajj is immediately obligatory according to the majority of scholars.

However, if he intends to return with his family to his home country and has no other usable dwelling, and he cannot combine Hajj with the necessary repair of his dwelling, then it is permissible for him to delay Hajj.

One of the conditions for capability (istita'ah) is that what one uses for Hajj must be surplus to essential needs such as housing, for a dilapidated dwelling is not considered a true residence. Capability is considered to be in surplus to what one needs for books and housing, or housing whose rent is needed for his own expenses and the expenses of his dependents.