Is there a contract or a prenup to sign in case of divorce?

The rules governing the Family patrimony and partition of the family residence are of public order and cannot be avoided even if a contract is signed between yourself and your spouse.

The rules governing the Family patrimony would also not permit you to recuperate or deduct the sums you invested during marriage, and this even though you had these sums before marriage. The only way to deduct these sums is if you invested sums belonging to you before marriage and which were in registered retirement plans. The rule is that the sums used must have been sums which would be partitionable as per the Family patrimony rules if they had been purchased or accumulated after the marriage. Non retirement savings are not partitionable under the Family patrimony rules.