Question about metal and wood foundation placements.

So my buddies and I were building a base together and we have done quite a bit of wooden structures around and then we started to make the metal stuff. Foundations, pillars, and so on. Well long story short we tried to make a square of wood foundations with walls (12 long on each side) to have a perimeter around our would have been metal fortress in the middle. Fact of the matter is, no where inside on the flat plain can we place the metal foundation. Is there in fact a radius that either foundation can not be next to? It seems foolish to ask but I don’t see why it can’t be done this way.