Rocheval revalues its two buildings to fair value at each reporting date. The revaluation surplus of the North building is 70,000; that of the South building is 5,000. After the year-end revaluation, the IAS 36 test of the South building, whose costs of disposal are not negligible and whose value in use is below the revalued amount, shows an impairment loss of 20,000. The accountant proposes to charge the whole loss to the total of the revaluation surpluses (75,000), which covers it comfortably. Which treatment should be applied?