The general rule is that it is the buyer’s responsibility to be satisfied as to the general condition of a property purchase. Provided the buyer is not misled by the seller, they cannot complain after exchange of contracts and completion as to its condition. When a mortgage is being obtained, a valuer on behalf of the lender will inspect the property, but  usually only to ensure that the value of the property is more than the amount borrowed. In practice generally the same valuer, on payment of a fee, will carry out a more detailed report, which can be relied upon if you, as buyer, later discover a problem with the property.