The Energy Policy and Conservation Act (EPCA) prohibits the Department of Energy from adopting efficiency standards that ban consumer access to appliances with distinct performance characteristics. In this case, the Department adopted standards abolishing gas-fired furnaces and water heaters that work with existing venting systems in millions of homes and buildings across the country. These standards will force consumers to either renovate their homes or switch to electric appliances.

The Department overhauled these standards by interpreting the statutory term "performance characteristic" to exclude features that allow an appliance to function in a home without renovation, dismissing that characteristic as a mere matter of "cost." App. 26a. Over Judge Rao's dissent, the D.C. Circuit deferred to the Department's statutory interpretation, asserting the statutory term required "case-specific" interpretation. App. 16a.

The questions presented are:

1. Whether courts may defer to an agency's legal interpretation of a statute because an agency applied the statute to undisputed facts, despite this Court's holding in Loper Light Enterprises v. Raimondo that courts must construe statutes without deference to agency statutory interpretations. 603 U.S. 369, 395 (2024).

2. Whether an appliance's ability to operate in existing homes and buildings without renovation is a "performance characteristic" that EPCA prohibits the Department from eliminating. 42 U.S.C. §§ 6295(o)(4); 6313(a)(6)(B)(iii)(II)(aa).

Whether courts may defer to an agency's legal interpretation of a statute despite the Supreme Court's holding in Loper Bright Enterprises v. Raimondo, and whether an appliance's ability to operate in existing homes without renovation constitutes a 'performance characteristic' under EPCA