Water Heaters in Unconditioned Spaces?

Occasionally a question arises, "Does a water heater located in an unconditioned space or outdoors trigger Title 24 Part 6 Energy Requirements?" The answer along with applicable code is below.

From the 2019 Building Energy Efficiency Standards:

SUBCHAPTER 1
ALL OCCUPANCIES—GENERAL PROVISIONS

1. Buildings Covered. The provisions of Part 6 apply to all buildings:
   1. That are of Occupancy Group A, B, E, F, H, I, M, R, S, or U; and
   2. For which an application for a building permit or renewal of an existing permit is filed (or is required by law to be filed) on or after the effective date of the provisions, or which are constructed by a governmental agency; and
   3. That are:
      1. Unconditioned; or
      2. Indirectly or directly conditioned, or process spaces.

   EXCEPTION 1 to Section 100.0(a): Qualified historic buildings, as regulated by the California Historic Building Code (Title 24, Part 8). Lighting in qualified historic buildings shall comply with the applicable requirements in Section 140.6(a)3Q.

   EXCEPTION 2 to Section 100.0(a): Building departments, at their discretion, may exempt temporary buildings, temporary outdoor lighting or temporary lighting in an unconditioned building, or structures erected in response to a natural disaster. Temporary buildings or structures shall be completely removed upon the expiration of the time limit stated in the permit.

   EXCEPTION 3 to Section 100.0(a): Buildings in Occupancy Group I-3 and I-4.

2. Parts of Buildings Regulated. The provisions of Part 6 apply to the building envelope, space-conditioning systems, water-heating systems, pool and spas, solar ready buildings, indoor lighting systems of buildings, outdoor lighting systems, electrical power distribution systems, and signs located either indoors or outdoors, in buildings that are:
   1. Covered by Section 100.0(a); and
   2. Set forth in TABLE 100.0-A.
3. Habitable Stories.
   1. All conditioned space in a story shall comply with Part 6 whether or not the story is a habitable space.
   2. All unconditioned space in a story shall comply with the lighting requirements of Part 6 whether or not the story is a habitable space.

So, the answer is only the current Residential Lighting Requirements apply to unconditioned spaces. A water heater in an unconditioned space does not trigger Title 24 Part 6 Energy Requirements.

As always, I am available to discuss the process of meeting the California Energy Code for any building project. Contact me …