International Residential Codes (IRC) regulate the design and construction of residential homes (not above three-stories). The code focuses on public health and safety from development through construction to maintenance of those dwellings. The IRC covers all aspects of construction, including building, energy conversation, plumbing, mechanical, fuel and gas, and electrical. The IRC's primary duty is to protect the public health, safety, and welfare of those residing in homes and townhouses throughout the world. Materials, design, and technology are all key elements considered in the review process to ensure compliance with the residential codes established by the IRC.