made a hutch for my brothers kids out of 12mm exterior ply [untreated ]which the rabbits cant get there teeth into except when the doors are open
4 years later sighns of wear and tare but nowt you cant fix with a new panel
the recomended size is much bigger than you think for a hutch
the base [cant remember exact size think it was 43" which allows the roof to overhang 2inches either side]was as you would expect an oblong with 2by2along all edges[underneath]this gives you somthing solid to fix the sides and back to and the batton at the front supports the floor [as you have your doors on all the frontage]it also gives you somthing solid for your bricks to sit under
none off it was treated
two trays made up to cover the floor area both sides eases cleaning and most rot happens on these [in the areas used as a toilet
type a few more details later if you like but getting boared at the min