Any home, new or existing, that can be field verified to meet all EPA requirements for ENERGY STAR Certified Homes can earn the label. Given that the verification process entails inspecting insulation and air barrier assemblies as part of the Thermal Bypass Checklist (TBC), it is unlikely existing homes will be able to qualify unless they are part of a gut rehab project exposing all insulated framing assemblies.
Where a new construction project has changed mid-stream to ENERGY STAR, the builder may ask a HERS Rater to field verify some completed units. Since the HERS rater is allowed to defer up to six TBC checklist items to the builder for verification, it may be possible to complete the TBC where remaining items can be field verified by the HERS Rater even though construction is complete (e.g., attic-side knee-wall air barriers). In this case and where all other field verification requirements are met, a completed home may earn the ENERGY STAR label.
Many HERS raters have asked if they can use an infrared camera diagnostic in lieu of a TBC visual inspection. EPA has clarified the use of infrared thermography for TBC inspections.