IECC Q&A: Dwelling unit lighting in multi-family buildings

In this column, we will address some of the typical questions asked of our technical support team. As always, code opinions issued by International Code Council staff are based on published Code Council codes and do not include local, state or federal codes; policies; or amendments. This opinion does not imply approval of an equivalency, specific product, specific design or specific installation and cannot be published in any form implying such approval by the International Code Council. As this opinion is only advisory, the final decision is the responsibility of the designated authority charged with the administration and enforcement of this code. All code citations reference the 2018 International Energy Conservation Code (IECC) unless otherwise specified.

Dwelling unit lighting in multi-family buildings

Q: Does the charging language in Section C405.1 allow dwelling units to opt-out of the requirements in Section C405.2.1.1 or C405.2.2.2?

A: Yes, Section C405.1 redirects dwelling units in multifamily buildings to Section R404.1 and all other dwelling units to either Section R404.1 or Sections C405.2.4 and C405.3 without exceptions or modifying language. Therefore, none of the commercial lighting provisions of the energy code apply to dwelling units within multifamily buildings.

The code specifically states that dwelling units in multiple-family buildings need to comply with Section R404.1. This applies to dwelling units in Group R-2 buildings that fall under the definition of “Commercial building.” Those that are residential buildings will also require compliance with Section R404.1 of this code. The section goes on to address “other dwelling units” and sleeping units. Other sleeping units are a rare commodity. These can be a guest suite in a Group R-1 hotel that has all the elements that define a dwelling unit or there might be an owner’s penthouse dwelling unit on the top of an otherwise commercial building. For such other dwelling units, the code provides an option of complying with Section R404.1 or the cited provisions of Section C405. Sleeping units, on the other hand, must comply with Section C405.2.4, which requires automatic shutoff of luminaires and switched receptacles and then allows the option of either complying with Section R404.1 or C405.3.

If Section R404.1 is selected as the compliance path for dwelling units not in multifamily buildings, the commercial lighting provisions do not apply. Otherwise, if the commercial provisions are selected as the compliance path for dwelling units not in multifamily buildings, Section C405.2.4 applies and it requires dwelling units to comply with either Section C405.2.1.1 or Section C405.2.2.2.