An appraiser is an impartial professional who can do a thorough revision to a property before buying it to ensure everything is in the required standards of quality.
Usually, buyers hire appraisers when they want to be sure the price they're paying is fair for the property. The appraiser is also going to issue a report with all the aspects of the property explained in detail and ways to improve them to increase the total property value.
This procedure is done by assigning a dollar value to each aspect of the property and adding them up to a total amount that is then compared to the amount being paid.