Legal analysis: the division between buying a house before marriage and buying a house together after breaking up is: (1) If there is an agreement, it shall be divided according to the agreement; (two) there is no agreement, according to the principle of equal consultation, reasonable division of common property; (3) If negotiation fails, the people's court shall reasonably divide the joint property according to the amount of co-owners' contribution to the joint property and their respective contribution ratios.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 1046 Marriage shall be voluntary by both men and women, and it is forbidden for either party to force the other, and no organization or individual may interfere.

Article 1047 The age of marriage shall not be earlier than 22 for men and 20 for women.

1048th lineal blood relatives or collateral blood relatives within three generations are prohibited from getting married.

Article 1049 If both men and women want to get married, they should apply for marriage registration in person at the marriage registration office. Those who meet the requirements of this law shall be registered and issued a marriage certificate. The marriage relationship is established when the marriage registration is completed. Those who have not registered for marriage shall re-register.

Article 1050: After a registered marriage, a woman can become a member of the man's family and a man can become a member of the woman's family according to the agreement of both men and women.

Article 105 1 The marriage is invalid in any of the following circumstances:

(1) Bigamy;

(2) Having a family relationship that prohibits marriage;

(three) did not reach the legal age for marriage.