Past exam paper

Regarding the past exam paper P2 June 2007 Q2 c

Wader is reviewing the accounting treatment of its buildings. The company uses the ‘revaluation model’ for its buildings. The buildings had originally cost $10 million on 1 June 2005 and had a useful economic life of 20 years. They are being depreciated on a straight line basis to a nil residual value. The buildings were revalued downwards on 31 May 2006 to $8 million which was the buildings’ recoverable amount. At 31 May 2007 the value of the buildings had risen to $11 million which is to be included in the financial statements. The company is unsure how to treat the above events.

May I know about the sentence mentioned that “The buildings were revalued downwards on 31 May 2006 to $8 million which was the buildings’ recoverable amount.”. This is considered as impairment loss or revaluation loss? because the answer in acca mentions that it is impairment loss in the calculation part, but it mentions that it is revaluation loss in the theory part so a bit confused.

May I know how to differentiate between impairment and revaluation loss in exam question?

Thanks sir