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Indoor airPLUS

Indoor airPLUS Eligibility Update

Public Comment Response and Summary

After requesting, receiving, and processing public comment (October-November 2019), the Indoor airPLUS Program is pleased to share a summary and proposed next steps. Stakeholder comments were overwhelmingly supportive of the Indoor airPLUS Program expanding eligibility to projects that earn the ENERGY STAR label under the Multifamily New Construction Program for buildings 5 stories or below. Some stakeholders were also in favor of expanding eligibility for multifamily buildings above 5 stories to further improve alignment with other national home labeling programs (i.e. ENERGY STAR⇒Indoor airPLUS⇒DOE Zero Energy Ready Home⇒PHIUS+), similar to how these programs are aligned as certification prerequisites for single family and low-rise multifamily homes. EPA agrees that full alignment of these programs as certification prerequisites would be similarly beneficial in the multifamily high rise sector. 

EPA agrees with commenters about the importance of enhanced indoor air quality (IAQ) in tight, high-performance homes and buildings. EPA also understands the value of clear specifications that articulate best practices in building science for architects, designers, and developers, as appropriate for their building type. As noted by some stakeholders, the majority of the current requirements and advisories in the Indoor airPLUS Construction Specifications are applicable to buildings of all heights. However, the requirements were originally developed in the context of the low-rise housing market, and EPA maintains that certain key elements in the Construction Specifications would benefit from further development to capture IAQ best practices in high rise buildings.

Considering these factors and recent feedback, the Indoor airPLUS Program will update its eligibility criteria as proposed. In addition, the program will continue to explore specifications to expand the Indoor airPLUS label to include high rise buildings as soon as feasible. EPA believes a number of key topics must be addressed in label specifications for high rise buildings, including: 

  • Ventilation
  • Dehumidification
  • Compartmentalization
  • Moisture management (high rise facades, curtain walls, roof drainage, etc.)

As such, the Indoor airPLUS Program intends to revisit multifamily project eligibility for high rise buildings as it continues to make these important technical program revisions. 

The Eligibility and Verification Requirements of the Indoor airPLUS Construction Specifications will be amended and outlined in the Indoor airPLUS Policy Record 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) to earn the Indoor airPLUS label . 

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. 

These changes will be reflected in the Indoor airPLUS Policy Record which will be available online at  

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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.