garage top ADU doors / noise considerations

[Wen Y.]

Hello all,

a newbie here from Chicago, Logan Square area.

a two part post here...

there is a new ADU pilot program in Chicago, and I am planning to build a garage top ADU, move there, and then fix up my crumbling two flat.

still sorting out the chicken and egg problems of:

-- not knowing how much I can borrow from a bank, construction loan, without knowing how much the project will cost

-- how much I can comfortably afford the carrying cost for two years while the construction is going on... 

-- getting More-than-ONE-architect-to-call-me-back in this incredibly busy Chicago market [two architects just plainly threw me the $10k bill without even talking to me over the phone! (you want to remodel two flat and put up a garage top ADU? Stop writing emails, we don't need to know any more from you.) "pay us and we'll give you plans and don't bother to call us again, just ask the contractor to make it work even if you discover a giant sinkhole while you dig" type of situation],

-- getting a contractor who can give me a ballpark figure on construction cost [so that I can get back to the bank] with me not having selected an architect with a firmer plan, BEFORE I choose an architect, etc etc etc! 

I certainly understand people's time is money... and I often wonder how contractors may or may not want to spend time with homeowner's for a construction bid before seeing a dime.

anyhow...

I wonder how much noise will the garage-top unit hear when I come home at midnight, raising the garage door, closing the car door and the regular door?

roof / floorboard insulation?
special wall build to reduce noise?
special garage doors?
special garage door openers?

How have you west coast people navigated these chicken and egg problems of architect / bank / contractor / holding-a-full-time-job-six-days-a-week situations?

Thank you all in advance.

Wen.