You have to close structural then set up and close plumbing and then set up and close electrical before you can even set up and close for the CO.

Asbestos and/or lead paint & Underground tanks (even if they are inactive) are also problemsKnowing when the Roof, Electrical, Plumbing and Heating were last updated (even if only partially) and what was done can help when your agent is shopping the property to different companies.

However, without the proper inspection, I feel I just can’t really project my numbers as I have no clue what to expect (having surprises down the line like replacing all the plumbing, electric, termites, mold, etc).

We'll get quotes from other GCs, but we're sure the job would be much less expensive if we hired a bunch of individuals:- kitchens and baths- flooring- exterior repairs, siding, windows, gutters- interior and exterior doors (these seemed way high)- trim, paint- electrical- plumbing- appliancesBut this would all be very difficult to manage from afar.

I don't see any issue with renting out the room in the house since it has it's own plumbing (half bath) and entry to the main house is secure from both sides and maybe add a kitchenette. 

(Plumbing, A/C, roof, electricity, etc)Outline of budget0% - 20% down before starting the project33% when 1/3 of work is completed66% when 2/3 of work completed100% when 3/3 of work is completed

Come to find out, the builder didn’t have a plumbing permit and built the new house on top of the existing slab and existing 60 year old water lines.

Treat well and plumbing system.

What would it cost to put in HVAC, plumbing and electrical?

Things like plumbing, property maintenance, and other odd jobs.