Plumbing question for ADU conversion

[Jacob Jenkot]

Hello BP!

I am considering converting a detached garage to an ADU. Seems like I should be fine my the city, but they are pretty incompetent, that's another story though.

So the detached garage sits on the alley where the sewer runs. It’s an old building and sits on at least 8 inches of a concrete slab (what I have seen visually during some landscape work.)

The structure does not have plumbing, and I would want  plumbing roughed in for 1 bath, kitchen and washer. I am not sure exactly how to ask a plumber for this service, if a plumber even the correct person to call for this. Would I ask for plumbing rough in?

Also, I am thinking this will be my most expensive part of the project. Does anyone have a cost break down from a recent ADU conversion in the Denver area?

Thanks

[Bruce Woodruff]

Yes, you would call either a Plumbing Contractor or maybe better a General Contractor, who would work and manage the whole product and deal with the City.

NOTE - First thing to do though is to go to the City and ask if this is even going to be legal. I used to have difficulty in California converting garages because of the lack of Steel/Concrete PSI/vapor barrier. It may not be possible to do the conversion because of this and you would have to tear down the existing garage and start fresh. You want to know this before you start....