The tax credit for window replacements falls under the category of the non-business energy property credit. Tax credits for replacing windows are claimed with the tax return of the year in which the windows are replaced.
Existing homes that are principal residences are eligible for the non-business energy property credit when adding or replacing windows that meet certain criteria. Tax credits are also available for energy-efficient home improvements such as insulation, biomass stoves, roofs, doors, heating, ventilation, air conditioning, water heaters, geothermal heat pumps, solar energy systems, small wind turbines, fuel cells and skylights. Tax filers must review federal tax credit guidelines each year for changes in eligible items.