Looks great, (and it might even comply with any new DECC enclosure guidelines ;-) ) It's always good to see such thought put into the animals needs ...
We built this a few years ago now and cannot remember the total cost.
We keep EWD's, Barbata, Eastern blueys, short and long neck turtles and cunninghams in there.
Don't forget to check your local pool fencing regulations as in some areas ponds deeper than 300mm are considered a drowning risk and you are legal obliged to treat them as such.
i dont get the thing with the rat proofing, how does it work and do u lay the ird wire in first and then the pebbles over it, or the pebbles under it? thanks for sharing this with us fay, really appreciate it.