A house was built by taking a loan from the father, now will the father be considered a partner in it?

(2) Similarly, this person intended to purchase another house. To do so, he took loans from his paternal cousins, brothers, and various other people. He also consulted his father, who gave him 1.5 million rupees as an interest-free loan (Qard-e-Hasanah) on the condition that it would be repaid within one year. The man bought the house using that money.
The father is now demanding repayment of the loan, and the man is trying to repay it. He has also repaid some other debts. Now the question is: Do the father and other siblings have any ownership right in this house, or will it be considered solely his personal property?

الجوابُ حامِدا ًو مُصلیِّا ً

If the details stated in the question are indeed true and based on reality, and there has been no misrepresentation, meaning that the person in question took money from various individuals solely as a loan and not as a partnership then in such a case, it is only necessary to repay the loans to those individuals. They will not be considered co-owners or partners in the house merely because they gave a loan.
However, if the nature of the question is different (that is, the arrangement was something other than a loan), then the question should be asked again with clarification, so that the appropriate Shari‘ah ruling can be given.

مأخَذُ الفَتوی

كمافي الدر المختار:(ويملك) المستقرض (القرض بنفس القبض عندهما) أي الإمام ومحمد خلافا للثاني فله رد المثل ولو قائما خلافا له بناء على انعقاده بلفظ القرض وفيه تصحيحان وينبغي اعتماد الانعقاد لإفادته الملك للحال بحر. (5/ 164)۔
وفي حاشية ابن عابدين: تحت (قوله بنفس القبض) وذلك أن ظاهر كلام المتن ترجيح قولهما، فكان المناسب للشارح أن يقول: وعلى هذا ينبغي اعتماد انعقاد النكاح بلفظ القرض، وهو أحد التصحيحين لإفادته الملك للحال فافهم اھ (5/ 164)۔
وفي الدر المختار: (وتتم) الهبة (بالقبض) الكامل (ولو الموهوب شاغلا لملك الواهب اھ(5/ 690)۔
وفي الفقه الإسلامي وأدلته للزحيلي: حكم القرض: يثبت الملك في القرض عند أبي حنيفة ومحمد بالقبض، فلو اقترض إنسان مدّ حنطة وقبضه، فله الاحتفاظ به، ورد مثله وإن طلب المقرض رد العين، لأنه خرج عن ملك المقرض، وثبت له في ذمة المقترض مثله لا عينه، ولو كان قائماً. وقال أبو يوسف: لا يملك المقترض القرض ما دام قائماً اھ (5/ 3790)۔