Tractor height

[IRL]

Hi
If I build a small tractor/ run for my pekin duck and hopefully a couple of call ducks, how heigh does it have to be?
I'm thinking 2 or3 feet? I want it to be as short as possible without making the pekin uncomfortable. I am not concerned about getting in there for cleaning because I plan to make it with a hinged top.
Thank you!

 

[IRL]

Bumb

 

[Bleenie]

I built a small one last year that a couple bought for their Khaki ducks, it was about 3ft tall at the highest in the front. Thinking back, my Pekins would have fit into it just fine. I will try to find a pic of that coop.

I couldn't find the one I was talking about but here's another that I have kept ducks in & raised ducklings in. the run easily detaches from the coop.