Is it the owner's responsibility to change the lock without going through the handover procedures?

Legal analysis: Yes. It is an infringement for the owner to change the lock without obtaining the ownership of the house. Those who infringe upon civil rights and interests shall bear tort liability in accordance with the Civil Code of People's Republic of China (PRC). The civil rights and interests mentioned in this Law include the right to life, health, name, reputation, honor, portrait, privacy, marital autonomy, guardianship, ownership, usufructuary right, security right, copyright, patent right, trademark exclusive right,

Legal basis: Article 165 of the Civil Code of People's Republic of China (PRC). If the actor infringes upon the civil rights and interests of others through fault, he shall bear the tort liability.