How to subtract width/length of rectangle/box toward pivot point (e.g. towards center)

When I’ve got a rectangle/box, how can I subtract a specific width/length towards a pivot point. I’m working on a Grasshopper file for a cabinet. Currently the doors (in my Grasshopper file) use all the space between de side frames of the cabinet. I want to give them ~3mm space around all edges.

I’m aware that I can do this when I construct the rectangle, i.e. by simply providing different x/y values, but I’m curious if it’s also possible to resize a rectangle/box after it’s been created?

I’ve created this basic rectangle:

And the file: (6.5 KB)

Not sure how you want to use this but have you considered Offset Curve? (7.0 KB)

If I understand you correctly, this should do what you want: (10.8 KB)


Thanks @Joseph_Oster this was exactly what I needed!

Thanks @kev.r although this is the more correct answer to my question … and really good to know about, but the solution from @Joseph_Oster worked for me as well.