Indoor Air Plus Qualified Home

1. Become an ENERGY STAR Certified Homes Partner: Indoor airPLUS requires that all homes first qualify under the ENERGY STAR Certified Homes program. If you are not already an ENERGY STAR partner, register at energystar.gov to begin that process.

1. Register as an Indoor airPLUS Partner: Visit epa.gov/indoorairplus and complete the free builder partnership registration. There is no application fee to join the program.

1. Review the Construction Specifications: Download the current Indoor airPLUS Construction Specifications (Version 2) from the EPA website. Familiarize your team with all required measures across moisture control, radon, HVAC, combustion pollutants, pest management, and low-emission materials.

1. Engage a Qualified Third-Party Verifier: Identify a certified HERS rater or qualified energy auditor in your area who is trained to verify Indoor airPLUS homes. This verifier will conduct the on-site inspection for each home.

1. Build to Specification: Incorporate all Indoor airPLUS construction requirements into your building plans and processes. Coordinate with subcontractors to ensure compliance with HVAC, moisture, radon, and materials specifications during construction.

1. Schedule On-Site Verification: Once construction is complete (or at the appropriate stage), your third-party verifier conducts an on-site inspection, reviews documentation, and confirms all specifications are met.

1. Submit for Labeling: The verifier submits verification documentation to EPA. Upon approval, the home is awarded the Indoor airPLUS label and listed in the EPA's online registry.

1. Use EPA Marketing Resources: Access the Indoor airPLUS marketing toolkit to promote your certified homes to buyers, and consider applying for the annual Indoor airPLUS Leader Award if you certify a significant volume of homes.

Indoor airPLUS evaluates homes across six major construction specification categories, all of which must be fully met — there is no point-based scoring system; compliance is binary (pass/fail on each requirement).

Moisture Control: Requirements address bulk water management, vapor barriers, drainage planes, and humidity control to prevent mold growth. This includes proper flashing, drainage, and vapor retarder installation.

Radon Control: Homes must include a passive radon-resistant construction system (sub-slab depressurization-ready), including a gas-permeable layer, plastic sheeting, and a sealed sump pit. In EPA Radon Zone 1 areas, an active radon mitigation system with a fan may be required.

HVAC Systems: Heating, ventilation, and air conditioning systems must meet specific design and installation standards to ensure proper ventilation rates, filtration (MERV 8 or higher), and prevention of backdrafting. Duct systems must be sealed and tested for leakage. Fresh air ventilation must meet ASHRAE 62.2 standards.

Combustion Pollutant Control: All combustion appliances (furnaces, water heaters, fireplaces) must be sealed-combustion or power-vented to prevent carbon monoxide and other combustion gases from entering living spaces. Attached garages must be isolated from living areas with sealed walls and self-closing doors.

Pest Management: Homes must incorporate physical pest barriers, including sealed penetrations, termite shields, and proper grading to reduce the need for chemical pesticides indoors.

Low-Emission Materials: Carpets, adhesives, sealants, paints, and composite wood products must meet low-VOC (volatile organic compound) emission standards to minimize off-gassing of harmful chemicals into the indoor environment. Products must comply with referenced standards such as FloorScore, GREENGUARD, or equivalent.

Indoor airPLUS occupies a unique niche in the residential green building certification landscape as the only EPA-backed label focused specifically on indoor air quality for new homes. As of the most recent EPA data, over 300,000 homes have been certified under the program since its 2009 launch, making it one of the more widely adopted healthy home labels in the U.S. market. Its close integration with ENERGY STAR Certified Homes — the dominant residential energy efficiency program — gives it a built-in distribution channel and credibility that standalone IAQ programs lack.

The program's market relevance has grown significantly in recent years, driven by several converging trends: increased consumer awareness of indoor air quality following the COVID-19 pandemic, growing concern about wildfire smoke infiltration in western U.S. markets, and rising rates of asthma and respiratory illness. The EPA's addition of wildfire smoke protection guidance to the program reflects this evolution. Major production builders including Meritage Homes, David Weekley Homes, and KB Home have committed to building 100% Indoor airPLUS homes across their portfolios, signaling strong institutional adoption.

Compared to alternatives like LEED for Homes or the WELL Building Standard, Indoor airPLUS is narrower in scope (IAQ-focused only) but significantly lower in cost and complexity, making it accessible to volume builders. LEED for Homes and NGBS are broader sustainability frameworks that include IAQ as one component among many. WELL is more comprehensive on health but is primarily designed for commercial buildings and carries substantially higher costs. Indoor airPLUS is best understood as a complementary add-on to ENERGY STAR rather than a standalone sustainability certification, and its free-to-builders model has been a key driver of adoption.

The Indoor airPLUS program was launched by the U.S. Environmental Protection Agency in 2009 as an extension of the existing ENERGY STAR Certified Homes program. The EPA recognized that while ENERGY STAR had successfully driven energy efficiency improvements in new residential construction, it did not specifically address indoor air quality — a significant public health concern given that Americans spend approximately 90% of their time indoors and indoor air can be 2–5 times more polluted than outdoor air. Indoor airPLUS was designed to fill this gap by creating a voluntary, no-cost labeling program that builders could layer on top of their ENERGY STAR certification.

The program's construction specifications have been updated over time to reflect evolving building science and emerging health concerns. A major milestone was the development of Version 2 of the specifications, which incorporated updated requirements and added provisions for wildfire smoke protection — a response to the increasing frequency and severity of wildfires affecting air quality across the western United States. The program has grown steadily, surpassing 300,000 certified homes and attracting participation from major national production builders. The EPA also established the Indoor airPLUS Leader Awards program to recognize builders who demonstrate exceptional commitment to healthy home construction, further incentivizing adoption across the industry.