How do you set the area required for placing something?

[HomShaBom]

Different things require different amount of space to be placed, for example, an Ice Box can be built much closer to a Science Machine than a Crock Pot can... [Screenshot]

But in their prefab files I can't find anything that would affect this. How do you do it?
 
cookpot has MakeObstaclePhysics(inst, .5) and icebox does not, but i've tried adding it to a icebox and it had no effect so I know this is know what does it. This is used as one factor in determining how close other things can be built to it, but not how close it can be built to other things.

[Mobbstar]

In the recipe, there's a variable for that. The mod "architectural geometry" changes that one for chests, I think.

[HomShaBom]

I suspected it might be in the recipe, but I cannot find the definition for the AddRecipe function. Where can I find it?

[Mobbstar]

Recipe() is found in recipe.lua in the scripts folder.

 

Here's an overview of the possible arguments (you can skip one using nil):

Recipe("product",{ingredients},tab,tech_tree,"placer",min_spacing,requires_researchlab,number_of_items)