planning garage studio - one room or two? Layout ideas?

This forum has really made a difference in planning my studio over the last several months. Gracias to all who put their blood, sweat and tears into helping construction and acoustics challenged musicians like myself design and build a home studio. Having read so much useful info, I'm ready to post my questions. I'm in Albuquerque, New Mexico in the planning stages and am a keyboard player/guitarist songwriter. I write rock-oriented, sonically adventurous (overproduced?) pop songs, both secular and Christian, and compose for and play in a a worship band at a local church, as well as playing solo gigs. I want the space to be for writing and producing my own CD's primarily. In that regard, my first priority is to be able to walk in and play/sing without thought of being heard outside the room(s), and to be able to capture the initial inspiration easily. My second prority is to use the studio as a songwriting tool - the third priority being to produce those tracks, using synthesized and/or V-drums, later to be taken to local studio for adding live drum tracks and for mixing. Fourth priority is to be able to rehearse by myself and with the band I write for (using V-drums) and bass/guitar amps at a reasonable volume without worry about isolation. I play an amplified baby grand piano, synth controller and/or acoustic guitar while singing in the equivalent of a PA (or monitors) initially, sometimes with a drum track and tend to like it relatively loud for inspiration. I also tend to monitor during production at relatively loud levels in general. All my gear is in storage, so I can't test the volume for a more exact description - sorry! The space in the garage of my recently purchased house is depicted in my rather crude SmartDraw attachment. My neighbors are quite close, especially on the left side (the inset side), and it's a very quiet neighborhood. I really don't want to be heard outside the garage at all, if possible. The garage is finished and has vents fo HVAC (which I plan on not using - plan to have the room completely isolated). It was formerly used as a sales office for the neighborhood homes and has 1/2' gypsum over some fiberglass insulation (not sure what kind, but standard for garages I'm told). Per code, I can't change the outward appearance of the garage door or three existing windows, but plan to, as much as possible, permanently cover and soundproof them on the inside, and build a room within a room inside of the existing structure. There is a pitched roof with some space above the existing 9"4" ceiling, with a light layer of fiberglass insulation (I doubt that I've got the budget to expand the ceiling as I've seen some do, but rather drop a new one). As you can see, there is a 2' inset on the left front of the garage for an existing small office space (10X10), which I'm going to gut as it's attached to the existing structure in ways that would compromise islolation. I did not include that in my drawing. The red dotted lines represent planned new wall construction to complete the proposed space. The proposed wall at bottom left will be adjacent to my wife's floral business/laundry room. Hope that's enough detail to get started. I'm glad to give more if necessary. I have between $20,000 and $25,000 for the construction and acoustics and about the same amount for buying a new computer, a ProTools rig with console, a new controller (my old one just died) and probably new speakers ( I have some near field Tannoys currently). I have a friend who is construction savvy who will help me build this, as I have No construction experience or talent whatsoever myself. Q#1 - Given budget, the available space, and my first priorities being to capture initial song ideas and then being in the control room with them, I'm struck by the fact that I'll be alone or with one songwriting partner 75% of the tiime. I've been wondering whether I should have a one room project studio, perhaps with a small vocal booth, or go for control and live rooms. I'd love to have a live room for piano and the like, but am concerned about having enough money for adequate isolation and acoustic treatments and having enough space to rehearse as well. I realize that ultimately I have to make that call, but I'd really appreciate any help in how to think about that decision. Reading has been helpful, but I need some direct feedback about it, if possible. I realize I may need to digest what you think and make a decision before you answer #2, but if you're clear in your mind which way I should go... Q#2 - John, you and I traded some initial emails a few months ago when I was inquiring about paying you to consult. Given my budget, I don't think I can make it worth your while, and still build it, but I'd appreciate some design ideas from you, and anyone else, given your humble opinion about Q#1 and the few irregularities in the shape I've proposed. Q#3 - After these questions are answered, should I then shift to the construction site for specific questions related to isolation and the like? Thank you in advance for taking the time to invest in helping me plan my studio...Let me know if you need other info in order to be informed enough to answer my questions. Paul Marcus

here's the plan.

Thank you, John. I appear to have made a critical error and sent the wrong drawing. In the new drawing, I have a bit more room. My sincere apologies. Attached is the correct one.