Hi Marcos, and Welcome!
That's a reasonable size and shape for what you want.
We were discussing dimensions, golden ratios etc
Actually, there is no such thing as one single "golden ratio". There are many good ratios, which are useful for different purposes, and there are many bad ratios as well, but there is no single ratio that is better than all others. There are rations named after the scientists who discovered them, such as Sepmeyer, Louden, Volkman, Bolt, etc. and each of those people discovered several ratios, so you will often see comments like "I'm going to use Sepmeyer 3 for my room". In the case of Bolt, he discovered that there is a range of good ratios that includes all of the others, and he showed a graph of all possible ratios with the area of "good ratios" highlighted. That area is known s the "Bolt region" or "Bolt area". As long as your ratio inside that area, it will be reasonably good.
I did not check your ratios, but you can do it yourself using these two room ratio calculators:
http://www.bobgolds.com/Mode/RoomModes.htm
http://amroc.andymel.eu/
So I would suggest that you use those calculators to find a good ratio for your control room, then make your live room a little larger with enough space to fit in all of the people and equipment that you need. The live room does not need to have an excellent ratio: as long as it is not a bad ratio, then you will be fine. Ratios are only critical for the control room, not so much for the live room.
isolation isn't MUCH of an issue.
What about noise coming the other way? Wind, rain, thunder, hail, aircraft flying overhead, traffic on nearby roads, trains, ships, animals, lawnmowers, people, nearby machinery, equipment, factories, sirens, river, ocean, etc. There are many, many external sounds that could mess with your recording sessions.
Rather than guess at how much isolation you need, you should test that using a sound level meter. Take several measurements in the location where the studio will be built, at all times of the day and night, to find out how loud it is there, and what types of noise could create a problem, as well as to figure out how quiet you need to be.
We were wondering if there's a sketchup design already made that's similar to this idea,
There are many, many designs on the forum, both professional designs done by John and other designers, as well as designs created by forum members with our help and the help of other forum members. There might be designs that are similar to what you need, but do be careful: All studios are different, and each needs its own individual design. It usually is not a good idea to copy something that was designed for a different purpose or location and just try to scale it up or down, or move walls around to make it fit your needs. You can do that if you have an really good understanding of acoustics, but not if you are just starting out. Many studios used tuned devices for the treatment, or specific angles, and those only work for that exact shape and size of studio. If you copy it and change the shape or size to fit a different situation, then the tuning will be wrong, and the angles will be wrong. So do be very careful with trying to copy plans for other studios: they might not work for you.
since (as you can see) we're so inept at drawing.
Take the time to learn SketchUp! You will absolutely need that. There are many good tutorials on YouTube about how to use SketchUp. You
cannot build your studio until you have a complete, fully detailed, dimensioned plan that includes EVERYTHING that you need: walls, doors, windows, HVAC, electrical system, seals, layout, geometry, materials, etc. Building without a detailed plan is guaranteed disaster.
He can't really afford an acoustic engineer, so that would be really helpful.
If you can't afford to hire a studio designer for a ground-up build, then there is something wrong with your budget! The cost of a designer's fees are just a very small part of the total cost of building a studio from scratch.
But anyway, if you don't want to hire a designer, then you will have to learn how to design it yourself. You will need two books: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics), and "Home Recording Studio: Build it Like the Pros", by Rod Gervais. The first one will teach you all about the basics of acoustics, and realistically it will take you about 2 or 3 months to do that. The second book will teach you about actual construction design, and you will need another 2 or 3 months to learn all about that. Then you will be in a position to design your studio. The actual design process will take you about 4 or 5 months. So if you want to do this yourself, without a designer, then you should allow at least 8 months, and probably one year would be better. Then you will be able to start building the studio. It would be a serious error to start building before you are ready! If you look over the forum, you will see a few cases where people did that: they started building before they had a complete design. In all of those cases, they ended up with major problems where they had to take down what they had just built, and re-build it correctly.
So that would be my suggestion: Buy those books and read through them carefully, then look at several of the design and construction threads on the forum, of members who already completed the process, so you can learn from them. Then learn SketchUp, and start designing your place. Feel free to post the preliminary designs right here on the forum, and ask all the questions you want about that, or about any part of the books that you don't understand. We'd be glad to help you improve your design, as it progresses, then to watch the actual construction in a year or so from now, when you are ready to do that.
- Stuart -