The window must be Energy Star certified. You can check the manufacturer's website.
See this Energy Star website - https://www.energystar.gov/about/federal_tax_credits
Federal Tax Credits: Windows, Doors & SkylightsWindows, doors and skylights that earn the ENERGY STAR save energy, improve comfort and help protect the environment.
Tax Credit Amount: 10% of cost
Note: There is a total credit limit of $200 for windows/doors/skylights for all years since 2005. For purposes of figuring the credit, do not include labor costs.
Requirements:
Must be ENERGY STAR certified
