Home Office to Mix/Production Room

[LookLikeAPhantom]

Hey Everyone,

I live in the Seattle area and I've recently moved into a new home. I would like to convert my home office into a mix room.
I've been reading the Gervais book, as well as watching some videos and using other online resources (like this forum). There's a ton of information out there and I'm just trying to wrap my head around everything, figure out what will produce the best (and most cost effective) results, and then chart a path forward on what needs to be done. I'm wondering if you are able to provide some guidance/consultation for something like this, or if you know of a service that does.
As I said, I'm only looking for a room to be able to mix and do some production. The loudest thing that I would be recording is vocals. The loudest that I would ever be mixing is between 80-90 db. I'm looking for isolation for any sound that would go out of the room, as well as isolation from noise made by other things and people in the house (talking, television, etc). We do live under an approach/departure path for the airport so we do get aircraft noise but I'm not terribly concerned with that, as I'm not going to be recording enough to need a lot of isolation from that. If I COULD cost-effectively get enough isolation from aircraft overhead, it would be a nice bonus, but if that would drive up the cost substantially, it's not something I need.
Some basics about the room (I've attached a screenshot of a sketchup model below, as well as a framing diagram I was able to obtain for the model of home that I have)...It's a 2nd story room that sits atop crawl space (Crawl Space Zone #1 in the framing diagram). It's about 13.5x14.5 and 9ft tall. The walls are regular drywall...I'm guessing 1/2 inch but I'm not positive. There are 3 windows, including two large sliding ones on one wall. I know this isn't ideal but I would like to have the windows included in the design because I love the natural light as well as the view. The door is currently one of those "farmhouse" sliding doors. Even when it is closed there is no type of seal so obviously that door absolutely has to go in favor of a door that actually closes and seals. The ceiling also has a light, an hvac vent, a smoke detector, and a covered sprinkler head (the home has a fire suppression system) that I would have to contend with.
So as I said, I'm just trying to figure out what the best way to go about this would be. I'm sure either way, it's going to involve tearing the original dry wall out and replacing with 2 sheets of 5/8, but then I'm trying to figure out if I should do a double wall, a staggered stud wall, a resilient channel, or a combination of things. I also don't even know where to start regarding what I should do for the floor and the ceiling. I've been in touch with a structural engineer but they can't really be of much help until I figure out the design of the room.

Any advice you can give on how to proceed or people to reach out too would be fantastic!

[DanDan]

Can't see that framing diagram, but no matter. Is this an upstairs room, i.e. on the second floor. In which case is your isolation requirement between this one and below? Or are there people on another floor above? Forget about the Aircraft, insurmountable. Windows allow Bass to escape through them. Plus visuals, very welcome.

[gullfo]

the simplest thing for isolation - add a layer of 5/8" type-x drywall on the existing walls and ceiling, build or buy interior windows to increase the isolation there - even 1/2" polycarbonate windows fitted over the existing ones (inside, perhaps on hinges so you can open and close them like a shutter or egress) would do a lot.

then with a minimal additional space taken up, add in the acoustic room treatments which should help reduce overall levels in the space (as well as even out frequency response and timing issues). consider ceiling soffits for absorption as this keeps your floor space open and provide a significant amount of absorption into the space.

later, if your hvac (you will need air in their even if you don't seal the door (which you should do as well) is now noticeable, you can build a silencer/plenum to fit over it to quiet that down.

[LookLikeAPhantom]

Can't see that framing diagram, but no matter. Is this an upstairs room, i.e. on the second floor. In which case is your isolation requirement between this one and below? Or are there people on another floor above? Forget about the Aircraft, insurmountable. Windows allow Bass to escape through them. Plus visuals, very welcome.

This is a 2nd floor room. There is no room below...just crawl space. There is a bedroom above the room, however we don't use it as a bedroom...just a workout room. Ideally, I would have enough isolation that I could mix at around 80-90 db at night, or record a vocal, and not disturb anyone in the house. There are two walls with windows. One faces the backyard, behind which is a vast forest area, and then the other faces our neighbors' home...which is about 20-30 feet away. Shouldn't be a problem with leakage over to them. Again...I'm not recording drums or anything crazy like that in this room.

[LookLikeAPhantom]

the simplest thing for isolation - add a layer of 5/8" type-x drywall on the existing walls and ceiling, build or buy interior windows to increase the isolation there - even 1/2" polycarbonate windows fitted over the existing ones (inside, perhaps on hinges so you can open and close them like a shutter or egress) would do a lot.

then with a minimal additional space taken up, add in the acoustic room treatments which should help reduce overall levels in the space (as well as even out frequency response and timing issues). consider ceiling soffits for absorption as this keeps your floor space open and provide a significant amount of absorption into the space.

later, if your hvac (you will need air in their even if you don't seal the door (which you should do as well) is now noticeable, you can build a silencer/plenum to fit over it to quiet that down.

I've never heard of the ceiling soffits before. I'm going to look into this. Is there an example somewhere?

Also...the room has a vent from the existing central AC. If I did something like two 5/8 sheets of gypsum on the walls (and potentially ceiling)...is that enough to warrant exploring a different hvac solution or do you feel that the existing hvac setup would still work for that?

[gullfo]

here's an example of the framing. basically 2x2 on 24" o.c.. this one is about 12" high and 18" deep. fill the bottom with semi-rigid - 4", and the top with R30 batts. cover the lower and room side vertical frame with cloth.