Each item insured under this memorandum is declared to be separately subject to the following condition of average, namely:
If at the time of reinstatement the sum representing eighty five (85) percent of the cost which would have been incurred in reinstatement of the whole of the property covered by such item had been destroyed exceeds the sum insured hereon at the breaking of any fire or at the commencement of any destruction or damage to such
by any other peril herby incurred against then the Insured shall be considered as being his own insurer for the difference between the sum insured and the sum representing the cost of reinstate net of the whole of the property and shall bear a rateable portion of the loss accordingly.
