How far do rabbits burrow?

Question

i have a Mini Rex rabbit he'll be 6 dec. 22 and my dad is building him a pen we want to buil under ground barracades so he dosent get out and i dont know how far they burrow help and suggestions appreciated

(p.s. my dad had the idea of a wire bottom then it will be like a big cage)

And were at sea level

Answer 1

they will burrow as far as you let them

i would say 1m max as you don't generally want them burrowing to far as if it turns you will never get them out again

Answer 2

they will burrow as far as they need