Article 1724 of the French Civil Code
If, during the lease, the leased thing requires urgent repairs that cannot be deferred until its end, the lessee must suffer them, whatever inconvenience they cause him, and even though he is deprived, while they are being carried out, of part of the leased thing. But, if these repairs last for more than twenty-one days, the price of the lease shall be reduced in proportion to the time and the…