The law as it pertains to rent-controlled jurisdictions. All lengths are common, though 12-month is perhaps the most common. In rent-controlled jurisdictions,

The law as it pertains to rent-controlled jurisdictions. All lengths are common, though 12-month is perhaps the most common. In rent-controlled jurisdictions, when a lease expires it converts to a month-to-month tenancy where the owner may only evict for good cause (failure to pay rent, gross negligence, illegal activities, etc), but a tenant must provide 30 days notice of intent to abandon. Often an owner is allowed to require a lease extension be signed, only if the extended lease is materially identical to the current lease except in expiration date (including length of the lease).