This Policy will indemnify the Insured, in respect of the difference in costs between those calculated at normal or standard rates of reimbursement, and those actually incurred including costs for overtime, work on public holidays and weekends, shift working and express freight provided that such costs:
(a) are necessarily and reasonably incurred by the Insured for the purpose of preventing or minimising any delay in completion of the Project solely due to insured Loss; and
(b) shall not include any costs for air freight; and
(c) shall not exceed the percentage, as specified in the Schedule, of the costs which would have been indemnified had this Condition not applied