He explains how he does lateral movement at 1:21 in the video. He's lifting the block enough to get an off-center pivot under it. Once the block is on a pivot

He explains how he does lateral movement at 1:21 in the video. He's lifting the block enough to get an off-center pivot under it. Once the block is on a pivot, he rotates it 180 degrees, then tilts it onto a new pivot and repeats. Because the pivots are off-center, each rotation moves the center of the block a little bit in the desired direction. At 2:08, they show the counterweights and one of the pivots he used for moving the barn. (It's a "pole barn", so it has no concrete foundation. His webpage says they had to add about 50% of its weight again in reinforcement so that it would hold its shape when moved this way.)