So, this mod allows you to copy any buildings into .litematic files, which you can then open in the Minecraft itself as a holography of the same building.
Litematica Mod for Minecraft 1.16.2/1.16.1/1.15.2
Thus, you can easily rebuild your houses, for example, from a single-player game, where you built it in creative, to the server, while not opening 2 minecraft at the same time, or remember where it stood, or take a screenshot from all sides! Well, or just see how your building will look in a certain place, and whether it will fit there at all.
A very useful addition will be that you can also see the amount of resources that you need for construction and even convert this number into stacks (for example, the mod may show that 281 stone blocks are “4 stacks and 25 blocks”)!