The document outlines methods for determining the percentage of completion of construction or renovation of residential housing in Ontario and British Columbia for purposes of transitional rebates and tax adjustments related to the implementation of the Harmonized Sales Tax (HST) on July 1, 2010. It provides definitions and an overview of the provincial transitional rebates available when housing construction or renovation was at least 10% complete as of July 1, 2010. It also describes how to determine the percentage of completion, noting it can only be calculated if work began before July 1, 2010, and that for new construction it begins when site excavation starts.