Windsor Limited entered into a construction contract to build a football stadium, which is considered to be a single performance obligation (i.e. building the stadium). Windsor Limited has a history of executing unpriced change orders, and it is not uncommon for Windsor Limited to begin work related to change orders after the contractor and customer agree to the scope of the change, but prior to the price being agreed. |

Requirement Based upon the information provided, when could Windsor Limited include the unpriced change order in contract revenue?