Property insurance policies routinely contain an appraisal provision. The provision may read something to the effect:
If you and we fail to agree on the amount of loss, either may request an appraisal of the loss. However, both parties must agree to the appraisal. In this event, each party will choose a competent and impartial appraiser within 20 days after receiving a written request from the other. . . . If they fail to agree, they will submit their differences to the umpire. A decision agreed to by any two will set the amount of the loss.