Who is responsible for maintaining the contractor's building?

Generally speaking, the responsibility for the maintenance of the house should be borne by the lessor.

According to Article 7 12 of the Civil Code, that is, "the lessor shall perform the maintenance obligations of the leased property, unless otherwise agreed by the parties."

The lessor shall regularly maintain the leased premises to make them in normal use. If the lessee finds that the house is damaged, it shall notify the lessor, and the lessor shall repair it in time, or entrust the real estate management department to formulate a maintenance plan and organize its implementation according to the damage of the house. When the lessor repairs the house, it shall take measures to reduce the impact on the lessee's use of the house. The lessee shall normally use the house during the lease period. If the house is damaged due to improper use by the lessee, the lessee shall bear the responsibility for maintenance.