What energy-efficient features should your replacement windows have? According to the Efficient Windows Collaborative (http://www.efficientwindows.org), a group of insulation and window manufacturers that comply with federal energy requirements, new windows should have low-e coatings, which let in visible light but block radiant heat losses to cut heating bills.
Efficient windows save money and energy. Just be sure they fit the house. Although there are no guarantees that the money you spend on replacement windows will be recouped when you sell your house, there are several good reasons to do it anyway. The choice is either to refurbish the existing windows to make them work as they were designed or to replace them with more energy-efficient models.
In new construction, standard windows are not that expensive compared with the total cost of the house. Special windows—transoms, half-moons, and Palladian—add a considerable amount to the cost, however. Windows in new houses, in fact, can approach 3 percent of the sale price. For a $300,000, 3,200-square-foot house, that means $9,000.