Our homes' windows are our eyes to the exterior world. They frame views, let in air and light, and make life spent in the great indoors more enjoyable.
But when windows malfunction, they allow heat to escape, moisture to come inside, and frost and condensation to form across the glass. Moisture and condensation produce mildew and mold, which can cause window frames and trim to rot. Consider replacing windows that leak air, are single-pane, or are hard to open and close. Leaky windows make furnaces and air-conditioners work harder, which in turn boosts fuel costs.
Replacement windows are a good investment. They will save you money in the long run, reduce fuel usage to help the environment, and add value to your home.
Weigh Your Options
Select windows that match your home's existing windows and/or architectural style and that satisfy your light, ventilation, and privacy needs. Review how different styles open and close, and if they tilt for easy cleaning. When you want privacy and windows with a streamlined appearance, look at models equipped with inset blinds. If sun damage to fabrics is a concern, check out windows with UV-protective coatings or tinted glass.
You'll save money if you replace existing windows with new windows that are the same size, style, and shape. Because new pre-hung windows will fit into (or across the top of, as in the case of some clad windows) existing openings, labor costs will be less. Replacing an old window with a similar version is a job that someone with strong carpentry skills can accomplish.
Check Material and Construction
Windows come with frames in different materials and glass with varying types of glazing. Check windows' ratings and replacement warranties to ensure you get the best value for your budget. R-value rates a window's heat transference in relation to its glazing and insulating traits; the higher the R-value, the better the window. U-value refers to the amount of heat flowing through a window; lower ratings equal higher energy-efficiency.
Click here to read recommendations from the U.S Department of Energy.
Vinyl, wood, fiberglass, and some composite frame materials provide greater thermal resistance than metal. Metal and aluminum frames are durable, light, and easy to maintain, but they rapidly conduct heat. Make sure metal frames have a thermal break -- an insulating plastic strip between the frame and sash.
Window Frame Basics
Wood frames cost more and are favored for their appearance and good insulation qualities, but wood can warp and shrink and require regular maintenance. Aluminum or vinyl cladding makes wood frames easier to care for. Composite frames made from particleboard and laminated strand lumber are very stable, have the same or better structural and thermal properties as conventional wood, and resist moisture and decay better than wood. Fiberglass frames, a midrange-price choice, are dimensionally stable with cavities that can be filled with insulation, giving them superior thermal performance compared to wood or noninsulated vinyl. Vinyl frames, among the least expensive options, are usually made of polyvinyl chloride (PVC) with stabilizers that protect against sunlight damage; they have good moisture resistance, and when filled with insulation, they are thermally superior to standard vinyl and wood frames.
Glazing and Glass
Different types of glazing and glass are available to suit each room's location. Gas fills improve the thermal performance of windows with insulated glazing. Heat-absorbing glazing supplies tinting that lets glass absorb incoming solar radiation to lessen glare. Insulated glazing describes windows with two or more spaced glass panes that are hermetically sealed. Low-emissivity coatings control heat transfer through windows with insulated glazing. Windows manufactured with low-e coatings can reduce energy loss by 30 to 50 percent. Reflective coatings block more light than heat. Spectrally selective coatings filter out 40 to 70 percent of heat while allowing in light.