I.-The lessor may refuse to renew the lease without being required to pay any compensation: 1° If he can prove a serious and legitimate reason against the outgoing tenant. However, in the case of either the non-performance of an obligation, or the cessation without serious and legitimate reason of the operation of the business, taking into account the provisions of article L. 145-8, the offence committed by the lessee may only be invoked if it has continued or been renewed for more than one month after the lessor has been given formal notice to cease it. This formal notice must, on pain of nullity, be given by an extrajudicial act, specify the reason given and reproduce the terms of this paragraph; 2° If it is established that the building must be totally or partially demolished as being in a state of insalubrity recognised by the administrative authority or if it is established that it can no longer be occupied without danger due to its condition. II -In the event of the owner or his successor in title rebuilding a new building containing commercial premises, the tenant has a priority right to rent in the rebuilt building, subject to the conditions set out in articles L. 145-19 and L. 145-20.