Mortgage valuation reports are requested by the lender before they make a formal mortgage offer.
A valuations of this type is a not proper house survey. It will not point out structural problems that you will need fixing and it will not outline any potential costs of repair.
Its only purpose is to confirm whether or not the property you want to buy is worth the amount you intend to pay for it, so the lender can decide whether you are eligible to borrow that amount.
The amount you pay for a valuation survey is based on the value and size of the property. Sometimes lenders offer mortgages with free valuation surveys but generally speaking, you are expected to pay for it.