At least it was just to do with the wiring. Frankly, Tony was relieved because he'd been teenaged once and holy god, he'd gotten up to some stuff in his room that should Never Be Spoken About. Stuff that he absolutely never wanted to accidentally walk in on. Hence the no barging in... thing.
"Stuff," he repeated, not at all missing the way that Peter was blocking the door a bit. Which was fine, it was his space or whatever. Just. Well, Tony was inherently nosy, particularly when it came to tech projects. And Peter was obviously good enough with them to not have been sticking forks into outlets.
"Noise is fine. Make all the noise you want." Probably not true - Bruce would probably object to that later. Maybe. But Tony was plenty noisy and that seemed fine, so. "Just -- uh. Nope. Don't need anything." Tony lifted his hands up in some vague gesture that was apparently supposed to further his words before his curiosity got the best of him. "What are you making? Are we going to need a backup generator?"