Structures not spawning right

Status
Works as designed
Issue description

I created a structures mod and all structures either spawn half floating off an edge or half buried in the ground or both. i set every structure to spawn on grass block. and when i created the structures i made a grass platform for them so i can have a floor indoors saved by the structure block. i will show screenshotS. how can i fix this?

Issue comments

If you want to spawn such a flat structure, you will need to either add more dirt to the bottom and use offsets to "burry it" or incorporate custom spawning conditions to detect flat surface.

The structure is simply placed on the world so this is totally normal without additional checks.