For existing buildings, the measure of total square feet leased (indicated as a Move-In) less the total space vacated (indicated as a Move-Out) over a given period of time. Sublet space and lease renewals are not factored into net absorption. However, in a lease renewal that includes the leasing of additional space, that additional space is counted in net absorption. Pre-leasing of space in non-existing buildings (Planned, Under Construction or Under Renovation) is not counted in net absorption until actual move in, which by definition may not be any earlier than the delivery date. (CoStar)