Legal analysis: this house belongs to pre-marital property. According to the Civil Code, if a husband and wife buy a house with personal property and mortgage a loan before marriage, the house is still their personal property and the mortgage loan is their personal debt. After marriage, one of the husband and wife participates in paying off the loan without changing the nature of the house as personal property.

Legal basis: Article 1063 of the Civil Code of People's Republic of China (PRC). The following property is the personal property of one spouse: (1) the pre-marital property of one spouse; (2) Compensation or compensation obtained by one party for personal injury; (3) Property that is determined to belong to only one party in the will or gift contract; (4) Daily necessities used exclusively by one party; (five) other property that should be owned by one party.