Divide a A3 document in two A4 documents

I have a house plan in A3 format.
In this plan I have the ground floor and the floor.
I need to print this A3 in two A4 documents (one with the ground floor and on with the floor).
So, i need to cut this A3 in two A4 without breaking the scale of the plans.
I don't know if I am being clear...

So I d like to know if there is a linux software that could easily achieve that.

If anyone knows... Thanks

Surprisingly simple:

sudo apt install pdfposter
pdfposter -s1 a3-input.pdf a4-output.pdf

pdfposter defaults to output to A4 by default (see man pdfposter for other options). All we have to do is tell it not to scale (with -s1) and it'll figure things out for itself.

Note that you'll need a printer that can print right up to the edges.