Indoor mews walls

[Peregrinator]

Hey everyone
I'm just curious if it would be legal and humane to have an indoor mews wall that is made of a sheet of some sort, for example, a tarp. I know that would save a lot of time and money (you could just hang it up) but would it be worth it? 
This is all out of curiosity since I am nowhere close to building a mews yet.

[SkyRider]

If the bird is incapable of reaching the walls, that should be fine. If you have a hawk that slices, it can help keep things clean by washing the sheets regularly as they get dirty.

The biggest risk you run is the hawk getting ahold of the sheets and getting a talon stuck. If it bates too hard to try and get away, it could rip the talon out. One of my friends birds landed on the carpet, went to jump up for a tidbit and his talon got stuck in a carpet loop and came right off.

You'd just have to keep the bird tightly tethered and triple check your knots every time.

[Peregrinator]

But would this serve as an adequate permanent mews? 

[megapode]

I would not do it because i am married and she barley tolerates a bird being the house for the time it takes to man it. I hang tablecloth or shower curtains obtained from the thrift stores behind the hawk. Others have kept a bird on a freestanding perch in the home with no sheets. Mostly longwings or single.
The only person you need to make happy is the one inspecting your mews, that includes your sponsor and a game official.