See if you can’t use the same elevator as fedex/ups or other regular delivery service – if they don’t use a freight elevator, you may not need to either. Your employer’s lease agreement may also contain some provision regarding bikes and common areas – and if the lease agrees with security guards, try talking with the building manager to get a reprieve during construction. I take my bike up an elevator everyday – be sure to place your drivetrain next to the wall so nobody’s work clothes get greased. Most people are appreciative once you explain why the bike needs to be on the rightside of the box.