Question on Ceiling Height

I just have a general question on ceiling height in a studio especially with how it pertains to getting a good drum and full band sound for rock/alternative music. I'm moving to a new home that has an attached, unfinished 1 story workshop with a flat roof dimensions are approx 15'wx20-23'lx9'h. 9 feet is up to the beginning of the rafters, I guess I have another 6"-10" above that to the roof. I am contemplating putting a green roof on top so there won't need to be a ton of insulation or sound proofing in the rafters. My question is, my own meager recording skills aside, will this be a good room to make a go at a part time studio that I would bring clients into, especially for drum recording and having a good "live" sound? Or is it better suited to a simple home studio and practice area and keeping my expectations lower? No budget is in mind yet since this question has been nagging me. I haven't closed yet so this is just the early preplanning, if anyone is curious to see here is a snapshot of the room: http://public.fotki.com/tpatton/philly/ ... f0135.html

What is a green roof?

Basically a roof garden, you cover the top of the flat roof with anywhere from 4"-12" of soil and plant flowers, grass, vegetables, etc.. It has a lot of environmental perks, helps with storm drainage and has insulating properties. I am assuming that much soil would also help with soundproofing. It's big in Europe and is catching on in the US, here's some examples: http://www.roofmeadow.com/assemblies/savannah.shtml

i think this is definitely one of those cases where you'll need some structural engineering as well as having someone with experience in designing green roofs - basically you're adding 20+psf static load to your roof which needs to be factored into the ability to handle the new static plus any live load. such as storage of rain water, etc that would be quite heavy... from a size perspective, it seems decent enough - you can probably get a good drum booth and control room in that space.

Thanks for the sketch! Yeah I def plan to have an engineer look at the idea, it really only hit me to try since the roof timbers are weak and need replacement anyway, so it is a good opportunity to beef them up. Would an all in one studio be wise? This will also be a band practice space so I want to make sure there is room for 4-5 people to play. I'm also considering having a bathroom available for studio use. Obviously I need to get in there and get more exact measurements.

Ok, I am dumb, after taking a closer look at my own photo an comparing notes with a coworker I think the room is closer to 30 feet than 20. Just to clarify a 9ft ceiling would be good enough for drum recording?

9 ft is decent