Assessments will be valid for 8 years after the date of assessment. However, printed and electronic Home Energy Performance Reports expire after 2 years from the date of assessment to ensure accurate utility rates and carbon emission factors, which are updated on an annual basis. After 2 years, sellers must go to the Registry to download a current report with updated information. Reports are void and invalid after an alteration or remodel of the home that affects the heated square footage, the quality and type of windows, insulation, HVAC equipment, or remodeled spaces such as basement or attic that are reasonably expected to impact the Home Energy Score and energy use estimates. These changes will require a new Assessment to be obtained prior to listing.