GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Water heating for cottage and detached garage apartment

vernacubuild | Posted in Mechanicals on

I’m building a small house with a detached garage/apartment. I really want to go all-electric, but gas is available.

I was considering two electric tankless, but plumber is recommending single gas tankless. In reading your blog, I believe the best option now is an electric tank in the garage to serve both and a demand pump in the main house.

I want an elegant all electric solution, but I also want it to be simple and cost-effective. Which option make the most sense?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. GBA Editor
    Martin Holladay | | #1

    There is no single answer to your question.

    It sounds like you live in a mild climate where plumbing pipes in your garage won't freeze.

    First of all, it's always a good idea to keep your plumbing lines short. So the answer depends partly on whether the kitchen and bathroom(s) in the main house are near the attached garage or are far from the attached garage.

    If the cost of the equipment were no consideration, the best solution would be two tankless gas water heaters: one near the faucets in the garage apartment, and one near the faucets in the main house.

    If you prefer an all-electric solution, you could install two tankless electric water heaters.

    Another option (since you live in a mild climate) is one or more heat-pump water heaters located in the garage. Like my other suggestions, however, that solution has high equipment costs.

    Because these solutions are expensive, you may have to compromise. For more information on these issues, see All About Water Heaters.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |