Need immidiate advice!

G'day all! I'm finding myself in somewhat of a pickle... you might remember a while back how I was asking a few general questions about designing a recording studio? Well anyways, it's turned into a huge project, and there are building codes and all sorts of things coming into effect now, demanding minor additions and changes to the plans. Well my problem is that one of the stairwells is going to have to push partway into the studio, and I'm worried about space. Right now the studio is about 600sq ft, and once the stairs push in, it will be cut down to about 550sq ft and have no sound lock. Is that an ok size to have an entire band in and such? I would like to have it as large as possible, and I'm considering relocating the actual studio within the building to give it more space. Please reply with your opinions ASAP, this is urgent, as constuction begins as soon as I'm done with the plans. Thank you all so much! Take care, TJ