Attics are frequently overlooked as potential living spaces for a home and are often used only for storage. However, a good architectural plan can transform even a small attic area into an attractive and comfortable home addition. Suitable replacement windows allow any attic to be converted into a light-filled and well-ventilated room which provides the homeowner with additional home space at a minimal cost.
Attics can be transformed into bedrooms, home offices, playrooms, guest rooms, studies or any other type of needed room. The cost of an attic renovation is minimal due to the fact that the walls, electrical structure, foundations and other basic home building necessities are already in place. The renovation project generally includes adding insulation, replacement windows, interior doors and any desired interior framing. Choosing the right replacement attic windows can go a long way toward renovating the attic room in a way that creates the desired architectural effect.
 Attic Window Considerations
Attic rooms have unique window needs in terms of venting, daylighting, insulation and legal codes. Attic windows, including windows for attic dormers and gable roofs, should be carefully planned to ensure good air circulation, privacy, energy performance and safety.
 Attic Ventilation
Attic windows should not be installed in a location that prevents or blocks air circulation or that creates energy suckers. Since heat rises, the heat of the home can heat up an attic room quickly, causing the attic room to become warmer than other rooms in the house. In addition moisture can increase in an attic room due to a build up of condensation. Adequate ventilation and insulation, including insulated windows, can prevent such overheating and dampness. If it is not possible to install a sufficient number of windows in the attic, additional air ducts, vents or ceiling fans can augment the existing windows to provide the needed ventilation.
Since attic windows are not easily accessible from the outside, it is important to plan ahead to ensure that the windows can be opened in such a way as to clean the outside of the window. In addition to self-cleaning glass, tilt and turn windows and tilt and slide windows provide this option for vertical sliding windows and horizontal sliding windows.
When installing replacement windows in an attic the architectural design should account for the rafters, angle of the roof's tilt and available space to guide the size, shape and style of windows to be installed. A creative attic architectural design may call for the windows to be installed in the ceiling itself or as window units which are comprised of a variety of window alternatives. Skylight windows are another design option for attic rooms. Skylights may be installed in either a sloped or flat roof.
 Energy Efficiency
The heat of the home rises into the attic, making the attic a warmer and cozier place during the winter but a more difficult room to cool during the summer. Remodeling the attic with adequate insulation, including quality energy efficient windows, helps to control the attic room's climate and can also aid in reducing moisture build-up. Windows which carry an Energy Star label are identified as windows which offer a high level of energy performance. The Energy Star rating includes ratings for the thermal insulation and the solar heat gain that the window presents.
 Attic Window Framing Materials
Replacement attic windows are accessible in fiberglass, vinyl, aluminum, wood, wood clad and composite frame materials.
 Wood & Wood Clad Frames
All-wood windows are traditional window frames which are often installed in Colonial, Western, Georgian, New England, Cape Cod and other "old" styles. Wood frames are good thermal insulators and fit in with "authentic" wood décors but many homeowners pass wood frames over because they require annual maintenance. For an additional charge homeowners can order wood clad frames in which the outside of the wood frame is clad in a weather-resistant aluminum or vinyl cladding, exposing the wood frame on the home's interior while protecting the exterior frame with the cladding.
 Vinyl & Aluminum Attic Frames
Vinyl frames and aluminum frames offer an economical replacement window solution for replacement attic windows. Aluminum frames are susceptible to condensation which may result in a build up of moisture in a warm attic room during cold weather. Both aluminum and vinyl frames are sold in a wide variety of color alternatives.
 Fiberglass & Composite Frames
Fiberglass frames and composite material frames offer a weather-resistant window option that is sturdy and durable. Fiberglass and composite frames generally cost more than vinyl or aluminum frames but are comparable in price to wood clad window frames. These frames are suitable for a contemporary or classic architectural style.
 Glazing Options for Attic Windows
An attic room's privacy, thermal insulation and radiation transmittance are affected by the attic windows' glazing. Choosing a suitable attic replacement window involves reviewing the glazing options and deciding which window glazing alternatives are necessary for each window application.
 Multi-Pane Glazing
The need to carefully insulate an attic room from the elements includes the necessity to ensure that the attic windows provide a quality energy performance. Attic rooms are generally the most exposed room in the house. Creating a comfortable living space in an attic involves insulating the walls and windows so that they provide adequate thermal insulation to the room. Multi-pane windows are an energy efficient window solution which prevent heat transfer, ensuring easier temperature control. Single pane glazing may be sufficient for an attic renovation in a moderate climate but homes in more extreme climates should install double pane replacement windows or triple pane replacement windows.
 Spectrally Selective Glazing
Maintaining a cool attic room is challenging in many climates because the heat of the entire house rises into the attic room. Spectrally selective glazing blocks the sun’s infrared radiation and helps to maintain a comfortable attic room temperature. These spectrally selective glazings ensure that the lowest possible amount of radiant heat is transmitted from the sun into the attic room which reduces the cooling expenses. Spectrally selective glazings include Low-emissivity coatings, tempered glass and tinted glass. Each glazing option offers a different level of sun protection. Tinted windows also increase the privacy level of an attic room.
 Attic Window Shapes, Sizes and Styles
Attic spaces vary widely in their sizes and shapes. These variations influence suggested window solutions for attic applications. Window options include non-operating picture windows, operating vertical and horizontal sliding windows, hinged casement windows and a number of special windows which are specifically created for attic installations.
 Operating Attic Windows
Ventilation is an important consideration when designing a renovated attic. Operating windows create a well-ventilated attic room. Suitable window options for attics include single - and double-hung windows, horizontal sliding windows such as the XOX and the XO models and both inswing and outswing casement windows. The small space of an attic room may indicate that an outswing attic casement window is the best choice to provide ventilation and save interior space. Depending on the window's size both casement and sliding windows can serve as code-approved egress windows which facilitate emergency exits or entrances if needed.
 Non-Operating Attic Windows
The unique construction seen in many attics opens the opportunity to include any of a number of special non-operating windows. These include dormer windows, skylights and special shaped windows.
 Dormer Windows
Dormer windows are installed in dormer attic rooms. These replacement windows are installed in the attic dormer structure and are the focus of the dormer formation which is seen protruding from the plane of a sloping roof surface. The protrusion creates a situation in which attention is centered on the window.
Skylights are installed directly in the home's flat or slanting roof to provide and disperse air and light from above the attic room. In colder climates skylights facilitate the sun's ability to warm up an attic naturally by funneling solar radiation into the room. In the same way, a skylight's glazing should be well-insulated to ensure that it does not overly heat up or cool down a room. Skylight options include shaft and cathedral skylights.
 Shaft Skylights
Shaft skylights are manufactured with a corridor that runs from the ceiling to the roof-line and then funnels natural light into the attic. These skylights are installed when the roof-line is more than a foot away from the ceiling.
 Cathedral Skylights
Cathedral skylights are installed flush with the roof line. They do not include a shaft. The glass panes are installed into a rectangular frame.
 Special Shaped Windows
Homeowners may choose any shape for a special shaped window. These windows may be installed as a section of another operating or non-operating window unit or on its own. Attic special shape windows include full-rounds, half-rounds, quarter-rounds, hexagons, octagons, triangles, rose shapes and any other desired special order shape.