Building a small vocal booth

Hi everybody. I need your help to design a vocal booth for an additional recording studio in Paris. My work is to localize products for France. I already have a studio, but i need to build another one soon. You'll find attached the sketch of the room where I want to build it. As you can see, there is not a lot of space. But I have to build a nice booth ("no room sound" required), and a small studio into the green area. All suggestions are welcome ! Thank you all (and sorry for my bad english) Greg

how 'bout you poste a 2d image (export from sketchup) here?

Here is the 2d screenshot thanks

which parts are existing and which is proposed? the elevated portion looks like a nice size so you'd probably just need to treat it.

Hi, In fact I'll build the studio and the booth in the green area. The walls already exist, and the windows too. I can't build anything in the red area, I must stay in the green one. Nevertheless, if you have any idea, I can get rid of the windows, or move the door. Thank you very much for your interest. Greg