AeroBarrier may be applied at any time between after framing inspection is complete and prior to occupancy. If you are building a new home, the BEST time to apply AeroBarrier is AFTER DRYWALL IS COMPLETED and JUST BEFORE PRIMER COAT IS APPLIED. The WORST time to apply AeroBarrier is at final stage – you will require to mask the ENTIRE HOUSE, which will be extremely costly and time consuming.