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Indoor airPLUS

Indoor airPLUS Eligibility Update

In coordination with the launch of the ENERGY STAR Multifamily New Construction (MFNC) program, the Indoor airPLUS Program will be revising its eligibility requirements to clarify which multifamily projects can earn the Indoor airPLUS label. As such, EPA is seeking stakeholder feedback on the following proposed eligibility requirements. Please submit comments by email to

The Indoor airPLUS Construction Specifications were originally developed as an addition to the ENERGY STAR Certified Homes label, previously for homes 3 stories or below and some multifamily properties in buildings of 4-5 stories.

Multifamily units that earned the ENERGY STAR label through the ENERGY STAR Multifamily High Rise Program (generally 6 stories and above, and some 4-5 story buildings with centralized mechanical systems) have not been eligible to earn Indoor airPLUS. Certification under ENERGY STAR Certified Homes has been maintained as the only prerequisite to Indoor airPLUS.
Under the new ENERGY STAR Multifamily New Construction Program, homes and apartments in multifamily buildings of any height can earn the ENERGY STAR. Some of these homes and apartments (e.g. townhouses and some units in 3-5 story buildings that were eligible for ENERGY STAR Certified Homes) would previously have been eligible to earn the Indoor airPLUS label, as well.

EPA’s Indoor airPLUS team recognizes that high rise buildings are often quite different from low- and mid-rise multifamily properties, particularly with regard to heating and cooling systems, mechanical ventilation, and water management components on the building shell. EPA continues to consider these elements and building science best practices for further technical development of the Indoor airPLUS Construction Specifications and expansion of program eligibility to include high-rise buildings. Until such specifications for high-rise buildings are developed, Indoor airPLUS is proposing to incrementally expand eligibility to projects that earn the ENERGY STAR under the Multifamily New Construction Program for buildings 5 stories or below.

As such, EPA is proposing to update the Eligibility and Verification Requirements of the Indoor airPLUS Construction Specifications as follows:

The following site-built or modular homes are eligible to earn the Indoor airPLUS label:

  • Detached dwelling units1  (e.g. single family homes); OR
  • Townhouses2 ; OR
  • Dwelling units in multifamily or mixed-use buildings with five (5) stories or fewer above grade3 .

Homes and dwelling units in single-family, multifamily, or mixed-use buildings that are five (5) stories or below and are newly built or undergoing a gut-rehabilitation must utilize the Indoor airPLUS Construction Specifications and must be certified under either ENERGY STAR Certified Homes or ENERGY STAR Multifamily New Construction (MFNC). 

Residential units in ENERGY STAR MFNC projects are eligible to earn the Indoor airPLUS label in buildings up to five (5) stories in height, including mixed-use buildings, where dwelling units and common space exceed 50% of the building square footage. Residential-associated common spaces, as defined by the ENERGY STAR MFNC National Program Requirements, must also meet the Indoor airPLUS Construction Specifications to earn the Indoor airPLUS label.

Requirements for both ENERGY STAR and Indoor airPLUS homes/units can be verified and reported simultaneously. Verification can be completed during the ENERGY STAR inspection process and must be conducted by a certified Home Energy Rater, Rating Field Inspector, or an equivalent designation as determined by an ENERGY STAR Verification Oversight Organization or Multifamily Review Organization. The homes/units must also comply with all applicable state and local codes and standards. 

The Indoor airPLUS Program is accepting public comment on these proposed eligibility changes through [30 days from posting]. Please submit to with the subject line “Indoor airPLUS Proposed Eligibility Updates”. Based on initial feedback, EPA will determine if the new eligibility criteria can be incorporated into a Policy Record update or if additional feedback will be necessary.

As EPA continues to develop revised specifications for Indoor airPLUS Version 2, EPA will be considering future updates to building eligibility and verification/oversight processes, while seeking valued public feedback from program partners, stakeholders, and IAQ experts.

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1A dwelling unit, as defined by the 2018 IRC, is a single unit that provides complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking, and sanitation.
2The term “townhouse” refers to a single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from the foundation to roof and with open space on at least two sides.
3Any above-grade story with 20% or more occupiable space, including commercial space, shall be counted towards the total number of stories for the purpose of determining eligibility to participate in the program. The definition of an ‘above-grade story’ is one for which more than half of the gross surface area of the exterior walls is above-grade. All below-grade stories, regardless of type, shall not be included when evaluating eligibility.