Test your understanding 5 On 1 January 20X1, Castle entered into a contract with a customer to construct a specialised building for consideration of $10m. Castle is not able to use the building themselves at any point during the construction. At 31 December 20X1, Castle had incurred costs of $6m. Costs to complete are estimated at $6m. Castle measures progress towards completion based on costs incurred. At 31 December 20X1 Castle had received $3 million from the customer. Required: How should this transaction be accounted for in the year ended 31 December 20X1