This also happened to us. We insured our house according to what it had cost to build as we had just done so and had all receipts, costs etc. Lender made us increase it according to Surveyors of Ireland guide, which we did. Then the lender did a valuation for final drawdown on build and as that valuation was higher they asked us to increase cover again. WE rang them and argued that the value was one thing but the cost was another and we weren't willling to increase cover a second time. They agreed!!!