I will assume that the project under construction is a major rebuilding of equipment or an addition to a building. The amounts spent on these projects would be debited to a long term asset account such as Construction Work in Progress. This account is often reported as the last line within the balance sheet classification Property, Plant and Equipment.
There will be no depreciation until the project is completed and the asset is placed into service. When the completed asset is placed into service, the project's cost will be removed from the account Construction Work in Progress and will be debited to the appropriate plant asset account.