Studio Renovation Sydney

Hi all. i spent a lot of time here back some years when i built my current place. time has passed, things have changed, and its time to update/ expand. basically, i want to extend the space to take up an extra few meters of the building, as since building the space i have bought a large analogue console (56ch DDA) as well as lots of other gear, and really need a bigger control room. CONCEPT: keep the drum room that already sounds great, and offers pretty good isolation. demo remainder of current studio (except the floor) and rebuild/ extend control room and second live space if possible would like to have a machine room/ cupboard for console power supplies/ pro tools computers/ tape machine etc. WHAT WE DO: record full rock bands, and mix them. THE BUILDING: this is the BASEMENT level of an old converted bar in sydney australia. though it is is a pretty strange basement.... we have cut a skylight (as shown) and ceilings are 3m, so doesnt feel like a basement at all. 3 of the outer walls are plaster/ brick/ earth with no common anything. the fourth (marked as entry) connects to my office EQUIPMENT: large analogue console. racks of outboard upright piano HD1 main monitors (no need/ dont want to soffit mount. though would consider soffit mounting other monitors and keeping the HD1 near/midfield) REQUIRED ISOLATION: this extension is not really about isolation. we are the only space on the basement floor, and dont really have any problems with noise. more about design and practicality and sounding good. BUDGET: 5000-7000 AUD. though much is already in place (floor, drum room, outer walls) attached is a simple drawing in sketchup just thinking of a way to get a big control room. as mentioned above, i would really like to keep the wall (well 2 angled walls) that make the drum room. it already sounds good, and isolation is pretty good. however i orientate things natural light to the control room (from skylight) is a must. and to other room/s would be nice? (thought of big sliding glass doors) any thoughts and feeling on other design options would be appreciated.