New roof, new water heater, new Electrical panel, New HVAC, new Concrete driveway, new Concrete steps & walkout basement, Open space of kitchen and living room, fully finished basement with wet bar and new full bathroom, new windows.

When turning basements into ADUs, and the breaker box, furnace, and water heater are down there, what are best practices for handling them?

There are many buildings with systems reaching the end of their life - Galvanized hot water risers, leaking vent stacks, aging window systems, outdated elevator and fire safety equipment.

Sometimes if you are renting the unit and it is not insulated properly, then you hear footsteps and conversations from next-door units, so tenants complain a lot, but there is not much you can do.Also, one time the unit above mine leaked water into my unit, and the HOA said I needed to talk to people living above mine to fix the issue and they didn't have the fund to fix the bathtub from leaking into mine, so I had to pay for the repairs.Sometimes working with HOA and is painful, but other times is easy if the unit does not have problems

Under the "moisture and/or water" section the sellers stated "water in basement during heavy rainstorm of june 2023. repair completed, sealed wall, added downspouts" with no mention what-so-ever about moisture....nor other walls that were painted over to hide water damage. 

Below are a few things I look for in a vacation rental cleaner:1) Hot Tub Maintenance: Since many of my properties include hot tubs, it's essential that my cleaners are experienced in testing water quality and adding the appropriate chemicals as needed. 2) Clear Communication: Real-time communication is crucial for me.

One unit has nearly the full back yard and has a lot of water irrigation.

Which is used to keep pipes from freezing but guess that doesn't particularly mean it's a water/sewer line 🤔 .  

@Rob Ibarra Converting non restaurant space into restaurant space can be fairly costly from what I understand due to the need for larger than standard water lines to service the building and a general need for grease traps and other restaurant specific infrastructure.My first question around going from abandoned auto shop to kitchen is zoning, could you even get the use approved, and then are their any environmental factors in play? 

It is located very closely to a Pond (+/_ 10-15' from edge of water to house); so it is very close.