The expression “co-owner at fault” refers to the concept of fault as described in articles 1457 and 1458 of the Civil Code of Québec.

Thus, the mere fact that damage occurs in a co-owner’s unit does not mean s/he is “at fault”; there must be proof that the co-owner was negligent.

A declaration of co-ownership that states the contrary could not be enforced against the co-owner in question (article 1074.2 of the C.C.Q.).