No insurer doing business in this State may issue a fire insurance policy for more than the value stated in the policy or the value of the property to be insured. The amount of insurance must be fixed by the insurer and insured at or before the time of issuing the policy. In case of total loss by fire the insured is entitled to recover the full amount of insurance. In case of a partial loss by fire the insured is entitled to recover the actual amount of the loss but in no event more than the amount of the insurance stated in the contract. If two or more policies are written upon the same property, they are considered to be contributive insurance, and, if the aggregate sum of all such insurance exceeds the insurable value of the property, as agreed by the insurer and the insured, each insurer, in the event of a total or partial loss, is liable for its pro rata share of insurance. This section does not apply to insurance on chattels or personal property.