Help with layout dimensions for garden studio/mixing room

I am about to build a studio in my garden in London Uk. I am a film composer/songwriter so will mostly be using it for writing /mixing , I also ideally need a vocal booth for solo instrument /vocals. I am getting a quote from a company that design prebuild garden studios which expect to come in at £20,000. I have attached screenshots of the planned layout and dimensions . The internal width 3.78 m and height 2.36 m are set in stone (planning reasons) but the length , currently 4.7 m could be altered either way by a meter if necessary. Also attached are screenshots of the detailed specs of materials etc... My main questions are : 1/ Which is the best layout for the speakers? As shown along the longer wall or the other way round along the shorter wall ie in front of the glass doors facing the back wall? ie which version is best 1/2/3/ or 4? 2/ Ideally I would like a vocal booth but worry that as I am limited for space I don't want to compromise the rooms accoustics by having a box in the corner. As recording doesn't happen that often I could just either use headphones or set up a removeable screen and monitor quietly . Would having a box in the corner create sound issues. 3/ Soundproofing : Does their spec seem sufficient given that I am not recording loudly and mixing film music mostly. Neighbours not that close about 5 meters from back roof of back wall of studio. 4/ Looking on this site most room designs have slanted side walls , is this really necessary for my purposes or could I just as well treat the room afterwards with some foam material for the reflections. 5/Should I be concerned about the front wall having so much glazing as it will have a different sound reflective value from the other walls. Also does that mean that I should reposition the speakers and desk ? 6/ For the ideal dimensions I have seen various ratios . Is there a calculator to work this out and what would be optimal for here? Thanks for taking the time to have a look at this. Charlie

Hi Charlie, Are you absolutely sold on this structure? The lack of symmetry is going to cause you grief with mixing. From what I can tell by looking at the wall systems, the structure itself is not designed with isolation in mind. 5 meters is not very far from your neighbour! This would be a nice building to paint in. I would not enjoy trying to mix in it. Steve

Hi Steve, Thanks for the response . I was starting to think I was not going to get a response as my post is a little basic compared to most on here. By lack of symetry, I could obviously lose the vocal booth and fill in the corner where the bookshelve is. I am not totally sold on the structure but I have no building skills and the prefab route seems the simplest and cheapest. I could be wrong and someone could build it for less than £20,000 but it's hard to find someone that builds music specific studios in back gardens. I get the quote back tomorrow so that will help decide. As far as my other questions I have discovered that the v1 is the best layout as the best place for the glass windows is behind the speakers . Again I could be wrong.re the isolation , is there anything I could tell the constructors to do to improve things? Sorry for being so untechnical. Charlie

if you were to go that route, #3 is your best option. use heavy drapes to block off the windows when needed. if high isolation is a concern, maybe fewer windows and re-arranging the interior walls to use isolation clips and hat channel to decouple the inner mass from the outer walls.

Hi, Would this layout be any better. Then I can put a heavy curtain at the back and fill in the recess (bookshelf) and maybe put a glass cover so that the room has glass effectively all along the front wall for symetry. I have been told that it is best to have the speakers pointing away from the glass as in the picture . In v3 I would be forced to close off the light by putting a curtain along the front wall which would not be ideal for dayly use.

i would flip it. put the desk on the wall and the couch in the corner by the windows