Abstract: An active moisture control barrier is provided which comprises a layer of shape memory polymer and a heating arrangement associated with the layer of shape memory polymer. The barrier may be used to provide an active humidity controlled space having an enclosure with walls to separate an interior of the enclosure from an environment surrounding the enclosure. An opening in one of the walls allows communication between the interior of the enclosure with the environment. A layer of shape memory polymer is provided at the opening to isolate the interior of the enclosure from the environment. A control may be provided for the heating arrangement to allow for a heating of the layer to a level as controlled or set by a user. An air passage conduit may extend from the interior of the enclosure through a zone of relatively higher water vapor pressure.