Building studio in garage

Hi there I’m planning to move my studio from the house to the garage. Therefore I need to rebuild it so it can be used. Because I’m from The Netherlands my measurements are in millimeters (meters) and excuse me if I write or spell this wrong. The garage is 3x6m and 2,3m high. It is a standard garage here in Holland. There is a concrete floor placed on sand, a single brick wall around, the roof consists of underlayment and some roofing. Below I will post some drawings I made. The detail drawing (cross-cut) A-A is for numbering. As first I want to place against the existing brick wall (1) a rock wool layer (2) of 70mm thick. Whereupon I place a second partition of cellular (4) at 70mm away from the rock wool (2) as it creates a gap (3) of 70mm. On the concrete floor I will place fixed pressure isolation (10) which I finish off with a wooden floor (11). On this I assemble a wooden frame (6) including rock wool between the styles (box-in-a-box). This frame will not touch the cellular which creates another gap (5) of 33mm, and stands on the floating floor. As last I will finish it off with some drapery and some wooden panels this will do the acoustics in the studio. Between the existing roof beams (9) I’ll use some rock wool (2)and there under a wooden plate (8). Below this comes the frame which doesn’t touch the roof layer also. Am I in the right direction with this. So if any of the experts here in this forum can help me with this I’m glad to hear.

I appreciate your extensive commitment, but please read this: PLEASE READ before you POST!! http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231 page and abide. This is for your benefit as well as anyone else that may come along.