These specifications were developed by the U.S. Environmental Protection Agency (EPA) to recognize new homes equipped with a comprehensive set of indoor air quality (IAQ) features. They were developed with significant input from stakeholders, based on best available science and information about risks associated with IAQ problems, and balanced with practical issues of cost, builder production process compatibility, and verifiability. Indoor airPLUS V1 (Rev. 01) contains the first revisions to the original Indoor airPLUS Construction Specifications issued in 2009. This revision is designed to: (1) improve the alignment of the Indoor airPLUS and ENERGY STAR for Homes requirements and provide a revised layout that clearly outlines the Indoor airPLUS requirements that are now satisfied by completion of the ENERGY STAR checklists and the additional Indoor airPLUS (Rev. 01) requirements that must be met to achieve Indoor airPLUS certification, (2) provide a clearer, simpler version of the Verification Checklist, and (3) provide alternate pathways to meet program requirements that address the wide variety of construction materials and techniques currently available.