Insurance relief

Hello Sir, (2) On 1 October 2012 an office building owned by Problematic Ltd was damaged by a fire. The indexed cost of the office building on that date was £169,000. The company received insurance proceeds of £36,000 on 10 October 2012,and spent a total of £41,000 during October 2012 on restoring the office building. Problematic Ltd has made a claim to defer the gain arising from the receipt of the insurance proceeds. The office building has never been used for business purposes. What will be the base cost ? Thanks