It is going to be 20 feet of wire just to leave the house. My service is at the northwest corner of the house. It will leave the house in the northeast corner and run 20 more feet to where the building would be. So 40 feet to get to the building, Then a small panel installation, and an outlet every 8 feet, so about 2 per wall minimum. More likely 3 per wall.

I can only gauge my normal electricity use, but since I had the panel upgrade done right before buying the house (I was a renter here for 4 years and the wiring did not pass inspection) I have not tripped a breaker. I used to have a workshop downstairs and I would try to use the table saw with the shop vac connected to it to suck on the sawdust. As soon as wood hit the blade and added some resistance to the motor, the breaker would trip. Once I had the upgrade to 200 amp and 6 more circuits put into the basement, all on 20 amp breakers, I can now do that simple thing with no concerns. I run a lot 24/7 here but it's all such low draw items my consumption stays relatively low. I have never done what a venue does for sound check where they push all the lights and power amps as far as they could every go to see if anything blows up. I just need it all done to code and everything will be fine. At any given moment the most I will have pulling power is a computer, the 32" TV that is my monitor, the 2 speakers, and a keyboard or guitar amp. I really don't use a lot of current because that's a single purpose room.

What is at the root of this decision is whether I want to spend $5000-ish on this novelty room I may use once a week if that often. It'd be slick to have a building dedicated to a music studio, but the other side of that coin is that I would also have 2 rooms in my upstairs I would never see again. I have 1200 sq feet here and that is very roomy for a single guy with a dog who never has company. The logic is that if I DID have this cool little "escape" room I might work more on music. I am in a complete rut the last year or so and I have no idea how to get out of it. I have no ideas for songs, my days are all exactly the same to the point where I oft7en check my mailbox on Sunday because unless it's football season I really don't know what day it is. Because I don't have to!