On my YouTube channel, Max Loren requested me to make this model that can be used to make the Barracks show the Reinforced Defenses upgrade.
During my response video, while making this model, I experimented with creating a custom Barracks model for this. However, this final version is made to work and interface with the exactly "Sprite Medium" attachment that is already included in the Barracks to define the location of its Spiked Barricades.
So you should be able to drop this model into your map, make a custom copy of the Reinforced Burrows Upgrade ability that uses this model, give it to the Barracks, and everything should look how it does in the attached image.