The best material for sunrooms in the United States is vinyl. Vinyl is an excellent choice due to its durability, energy efficiency, and affordability. According to the American Architectural Manufacturers Association (AAMA), vinyl windows have a life expectancy of 20 to 40 years, making them a long-term investment. Additionally, vinyl is a thermally efficient material that helps reduce energy costs by maintaining a consistent indoor temperature. A study by the U.S. Department of Energy found that vinyl windows can reduce heating and cooling costs by up to 15%. Furthermore, vinyl is easy to maintain and clean, requiring minimal upkeep. Its versatility allows for various styles and designs, making it a popular choice for homeowners seeking a sunroom that complements their existing architecture.