The (im)possible garage conversion studio

Hello brain-hive: I've done quite a few home studios, but this one's a first. I want to tell the client he's crazy, but I need some others to help me communicate that with more authority, or better yet, come up with solutions. Scenario: DIRECTLY under the take-off flight path of Burbank Airport, 90-100dB noise levels outside. Garage conversion to studio and a guest apartment with FULL KITCHEN/BATH. SINGLE ROOM, no partitions of any kind (wife requirement) Wants to record ADR/loop-group with up to 6 actors in the studio. Wants a SINGLE DOOR entry point, not doubled tandem doors or an airlock. Help me out here... George

You're limited by mass law. So unless the client wants lead walls, you're going to have troubles getting clean ADR. Greg

Greg, you're right. How do I communicate this to my overly optimistic and enthusiastic client who's already applying for building permits, hired an architect, a designer, and me as audio consultant?

Tell him that what he wants to do won't work. Offer him a solution that will work. He needs two doors, with a cavity. They need to be heavy. He could get 40dB isolation MAYBE with a single door. I don't think 60dB inside the room during recording is going to be OK for him though every time a plane goes overhead. You're the studio designer, tell him that it doesn't matter what he does to his walls, he will not get his door anywhere close to the isolation he needs without decoupled doors. Also how are you designing HVAC for high isolation? What about kitchen bathroom ventilation? Dan