Overview Replacement Windows
Windows provide varying degrees of light and ventilation but they also significantly impact on a home's heating and cooling costs. Choosing the right replacement windows involves a careful scrutiny of a window's properties including the window's weather resistance, thermal insulating capabilities, visible transmittance, heat transfer, shape, style and size.
 When to Replace a Window
A replacement window is installed in an existing window opening. Replacement windows take the place of existing windows when the existing windows have deteriorated, become drafty or no longer function properly. New replacement windows may also decrease energy loss and outside noise. Replacement windows include two types of replacement alternatives. Total replacement installations -- full frame installations -- involve the replacement of the entire window frame, sash and trim. Insert replacements refer to replacements in which a portion of the original installed window is replaced -- the window sash -- along with additional parts which are needed to install and insulate a new window sash. There are also available insert replacements for situations in which the replacement only involves the window sash.
Homeowners decide how to replace their windows based on individual needs and expectations. Homeowners who want to bring a different window style into their home or significantly widen or minimize a window opening may choose to replace the entire window, including the frame. Homeowners who wish to maintain the same general appearance and window size can buy a replacement window sash that replicates the original window.
The window's style is also an important consideration when purchasing replacement windows, especially for homeowners who want to change their home's appearance. Using a different window style can significantly impact on a home's new architectural design.
 Benefits of Replacement Windows
Replacing windows can offer an enhanced architectural look while, at the same time, they can increase a home's resale value and reduce heating and cooling costs. Homeowners who are preparing to replace their windows should research the different options carefully so that they fully realize all of the benefits that new replacement windows can provide.
 Window Styles
Replacement windows are available in a wide range of window styles including operating and non operating windows. Both types of windows add light to a room but operating windows open to increase air flow into a room. Operating windows are a more costly replacement window option due to the added cost of operating hardware that the windows require. Non-operating windows are also a more air-tight window alternative though high quality operating windows with good weatherstripping and spacer bars can block air leakage to prevent drafts.
 Framing Materials
The choice of a replacement window's framing material will impact significantly on the window's look and energy performance. Replacement windows are available as wood, wood clad, fiberglass, composite, vinyl and aluminum frames. Aluminum and vinyl windows are generally a less expensive window option but their effectiveness as thermal insulators is not as effective as high quality wood, wood-clad, composite or fiberglass frames. Wood windows, unless maintained annually, do not offer the weather resistance that the other framing materials provide. Wood windows with treated aluminum or vinyl exterior cladding -- wood clad windows -- protect the windows from the weather's elements. All window types are available in all available framing materials, though sturdier framing materials, such as wood-clad, fiberglass and composite materials offer more durable frame options for large window applications. These window alternatives include including large double hung, hinged and fixed frame windows.
 Glazing Options
Homeowners can increase the solar heat gain coefficient and reduce the U Factor for superior energy performance by ensuring that the replacement windows' glass is suitable for their specific climate and window orientation. Purchasing high energy performance windows involves reviewing available options for multi-pane windows, glass strength and window coatings. In addition to single pane windows, replacement windows are available with a choice of double panes or triple panes. These multi-pane windows slow heat transfer and increase a window's insulating capacity. Many window manufacturers pump argon or krypton gas into the gap between the window panes to further insulate the windows. Homeowners can order windows with Low E coating to enhance the solar heat gain coefficient and inhibit the transfer of Ultra Violet rays. The Low E coatings are climate-specific so consumers must order the correct Low-E coating for their specific location. Other glazing options include different types of glass such as strengthened glass, privacy glass, heat absorbing glass and Self Cleaning Glass.
 Sizes and Shapes
Many window manufacturers offer a wide range of standard size replacement windows which are less costly than custom-sized windows. Homeowners may purchase a standard window which is smaller than the existing window opening and fill the gaps around the frame with silicon or other filler. It is also possible to order a replacement window which is specially sized for a specific window application. There are also standard-order special shape windows but in general, special shape windows are a custom order. Special shape windows include many different window shapes including windows with curves and/or angles. Special shape windows include elliptical, full arch head, full cord, full circle, half cord, half circle, eyebrow, octagon, partial arch head, half elliptical, quarter circle, partial chord, pentagon, trapezoid, springline, Isosceles triangle and right triangle shapes. Window manufacturers can also create special shape windows to fit into dormer and gothic spaces. Protruding windows, such as roof lantern windows, garden windows and bay and [[Bow Windows|bow window units protrude from the wall or ceiling to add space, lighting and an architectural focal point.
 Energy Efficient Windows
 Tax Rebates and Refunds for Energy Efficient Windows
Making energy efficient replacement windows available and affordable is a goal of homeowners, consumer activists and governments. Many national and regional governments offer tax credits and/or rebates for purchases of energy efficient replacement windows. The qualifications for credits or rebates is determined by window ratings which are determined by the National Fenestration Ratings Council. Windows with suitable U-Factor and solar heat gain coefficient ratings are labeled Energy Star Windows. The windows' eligibility is determined by the windows themselves as well as the geographic region in which the homeowner lives. Many manufacturers offer several different levels of Energy Star Windows to meet the specific needs of homeowners in different climactic zones.