Planning Home studio - Live room and Mixing room

Hi, this is my first message in this forum.... having read the instructions I'll try to bring up the most info I can into discussion. Please note that I'm from Mexico, English is not my native language... so if I'm missing something please let me know. This is the situation: I'm a mixing engineer moving into a new location, which is under total redesign 'cause it´s a very old house. I'm working with an architecht, and the space we got for this project is about 6m x 2.5m in a 2nd floor. Currently this area is on the rooftop, so there are no walls or anything surrounding it yet, but those surrounding areas are already planned for other things. I want to have a mixing room and a recording room (Live room). I'm expecting the live room to be big enough for at least recording some drums... the mixing room will eventualy house a mixing desk of about 1.5 m long. About the budget... I want to put nice materials and stuff, but I'm still saving for it... isolation I think will have to wait a little. For now, I will start only with the structure, doors and windows... and well, the electricity matters and holes for the patch panels haha. All that said, I have a lot of doubts... 1.- Considering the size, is that a decent space for what I'm asking?, or should I start better planing just in a mixing room and maybe a vocal booth. Any ideas for dimensions will be greatly apreciated. 2.- What about the ventilation... the architect said me that he can design some ducts for cold air entry on the ground and some extractors up the doors for the heat, in a sort of "cycling air" system. Is this convenient? Air conditioned is an expensive option in Mexico city... 3.-As explained in the VERY rough drawing I'm uploading, the live room faces to the street... I don't know if it's a good idea to put a window there, but otherwise lights would have to be turned on all day :? . Also, I would like to have two windows in the control room... the one that faces the live room and one at the opposite site, also for some natural lighting. I know this last idea will very likely cause reflection problems, but well... just tell me if it's possible. 4.- Suggested height of the roofs?? Hope all of this information is useful to get a picture of my situation. Please, feel free to ask me anything I missed, I'll be looking this thread everyday ho ho... If pics needed of actual conditions, I can go and get some. Greetings. Rafa

That will be a pretty tight space. Check John Sayers' container designs to see what's possible. If you need isolation, I'd suggest doing it while constructing rather that try to retrofit later. I'd suggest a ceiling of 3.1m if possible.