ADU on existing garage slab – GreenBuildingAdvisor

Hello (and thank you for this opportunity!). Reading an older post (2011) about building in Massachusetts on a slab.

Currently speaking with a builder about converting an existing detached 2 car garage into an ADU.

My county and town finally are now allowing these to be built, but

I’m so concerned about a couple things. One is water supply from current and main home’s well into this build.

Water lines freezing is my big concern. And just a build in general on a slab is, too. Am I overthinking this?

Electric water heater will be placed in the unheated garage, and I still need to have a water filtration system installed.

Any concerns I should be asking, or be very aware of?? Other than frozen water lines??

Thanks SO much!!