The koi pool isn't that big so we built a small deck in front of it, sightly overhanging the edge, it gives the illusion the pool is bigger than it actually is.
The only 'discussion' we had was the placement of the rock around the spillway, I didn't quite like the angle some of the rocks were in, needless to say I ended up finishing it myself LOL.

Once that was built I thought why don't we lattice in the rest of it, I thought enclosing it in will make it look more like a room. Not shown in these pictures is the lattice we put up covering the fence, left hand side last year (first picture).

Coming up a gravel path you can see the spillway through a doorway, lattice walls on both sides. Eventually these will be covered with vines or maybe Actinidia kolomikta.
The whole thing inside the lattice walls is approximately 15'X20' give or take an inch or two. The deck goes along the whole length and is approx. 6' wide, wide enough for a small table and a couple of chairs. This is where I grow a few things that wouldn't make it outside, like the Daphne odora 'Aureo-marginata' in the right hand corner of the planter.
Things have matured a little bit since the pictures were taken but things are pretty much the same.

First picture left hand side, more to follow.

we have lost numerous sets of koi- small ones- to what we guess were herons and/or raccoons, so we haven't added any in recent years...sigh. Yours are beautiful.

Annette

Edited to add:
I had thought that it was attached to your house. How far away from the house is this area?

Annette