IAS-23 – Borrowing Costs :

The benchmark treatment is to treat borrowing costs as expenses. The allowed alternative is to capitalise those directly attributable to construction. If capitalised and funds are specifically borrowed, the borrowing costs should be calculated after any investment income on temporary investment of the borrowings. If funds are borrowed generally, then a capitalisation rate should be used based on the weighted average of borrowing costs for general borrowings outstanding during the period. Borrowing costs capitalised should not exceed those actually incurred. Capitalisation begins when expenditures and borrowing costs are being incurred and construction of the asset is in progress. Capitalisation suspends if construction is suspended for an extended period, and ends when substantially all activities are complete.