|Replacement Dormer Windows|
|Dormer windows extend outwards from the diagonal slope of a gable roof.|
Dormer windows are an integral part of a dormer architectural structure. The dormer window is set in a dormer unit and has its own roof that juts out from the larger roof. Dormer replacement windows are installed in the dormer structure and are the focus of the formation which protrudes from the plane of a sloping roof surface. Dormers occupy less than a half of the roof space and the windows are generally smaller than the windows below. The window of a dormer unit incorporates the features of the dormer structure and provide a ventilation opening that ensures that the dormer can be utilized as living space within the roof of a building.
 Dormer Window Styles
The style of a replacement dormer window is determined by the design of the dormer structure in which it will be located. Dormer windows include a variety of replacement window styles including flat, gabled, shed, hipped, deck, arched, oval, eyebrow and inset.
 Eyebrow and Oval Dormers
Replacement eyebrow and oval dormer windows are characterized by a lack of vertical sides and a low upward curve. They resemble a sleepy or half-opened eye. Eyebrow and oval dormer windows are often a feature of the Shingle style of architecture. Eyebrow and oval dormer windows create a focal point on the roof and many homeowners find them aesthetically pleasing. Because of their structure they must be custom made and involve a significantly higher cost than other window options -- approximately three times as much as a skylight window.
 Gabled Dormers
Gabled dormer windows are typical in English Tudor houses. They have gabled roofs which consist of two sloping planes that meet in the center. Gable dormer windows add light and ventilation to an attic space. Many homeowners appreciate them for their aesthetic appearance as well as for their functionality. They are generally a less expensive window option than other types of dormer windows but the pitch of the gable roof creates a more dangerous working environment for construction workers who need to access the outside of the window during installation, resulting in the possibility of higher installation costs.
 Hipped Dormers
Hipped replacement dormer windows are installed under hipped roofs which are characterized by three sloping planes which meet at the top. Hipped dormers are featured in prairie style and craftsman architectural style dormers though they can also work well with a wide variety of home styles. Improper sealing of a hipped dormer window can lead to leaks, mold and structural damage.
 Recessed Dormers
Recessed, or Inset dormer windows are a distinctive architectural style which are set back into the roof. Recessed dormers are a good choice for small roof areas which are not intended as living spaces. They allow for increased ventilation and natural sunlight. The durability of a recessed dormer replacement window is dependent on the materials used.
 Shed Dormers
Shed dormer windows are the simplest and most common form of dormers. They are set under a roof with a single sloping plane and are frequently found in Arts and Crafts and Colonial Revival architecture. Shed dormers are one of the larger dormer alternatives. The shed dormer window is generally a large window which is designed to ensure that the shed dormer room has adequate ventilation and light as a replacement shed dormer window maximizes the amount of sunlight brought into a dormer.
 Types of Dormer Windows
A variety of window types are used as replacement dormer windows. Homeowners choose the replacement dormer window type according to the architectural requirement for a ventilating or non-venting window, cleaning options and preferred operating style.
 Window Options
 Ventilating Dormer Windows
 Non-Ventilating Dormer Windows
Dormers which are roofed off on the inside and are not intended to provide extra venting are called "blind dormers." Fixed windows or picture windows are suitable window options for these openings and are often installed for aesthetic reasons rather than function.
 Cleaning Considerations
Because dormers are generally installed in a second or third story of a house a homeowner should plan ahead when purchasing an operating dormer window to ensure that the exterior pane of the window will be accessible for cleaning purposes. Dormer windows that offer options for accessing the both sides of the window pane for cleaning include tilt and turn windows, tilt and slide windows, pivot windows and inswing casement windows.
 Emergency Egress Dormer Windows
Dormer windows are generally at least 75% of the area of the dormer wall, enabling a dormer window to serve as an emergency exit window if the dormer is intended for use as a bedroom. An emergency egress dormer window must be sized to code to enable a person to easily exit the room through the window opening, or enable an emergency staff person to enter the window through the opening.
 Non-Ventilating Dormer Windows
Replacement non-operating dormer windows may include picture windows, half rounds, side-by-side quarter rounds, and other fixed windows of varying shapes.
Replacement dormer windows can be installed in any one of a variety of shapes and combinations including square windows, rectangles, oblongs, half rounds, side-by-side connecting quarter rounds, ellipses or half rounds set on top of a rectangle or square window. A dormer window may include two side-by-side vertical sliding or casement windows or windows that follow the pitch of the roof producing a slanted window sash top.
Dormer windows are available as small windows which measure as small as one foot in width or height or as large windows which can measure up to four feet in width or height. The size of the dormer room will determine the replacement dormer window size.
 Energy Efficiency
The framing materials, glazing, weather seals and quality of installation of a dormer window will impact on the window's energy performance. If the dormer is intended to be used as a bedroom, the homeowner will want to include an energy efficient window to increase the comfort level within the dormer room and save on energy costs. Emergency egress windows can meet the requirements of egress window codes while providing maximum thermal insulation.
The United States Department of Energy accepts the ratings of the National Fenestration Ratings Council which provides assessments of each window's capacity for offering thermal insulation and preventing heat transfer. The Council's U-Ratings are considered an industry standard. Energy Star windows with U-Ratings of 30 or less are acknowledged as providing homeowners with a quality energy efficient window.
 Framing Materials
Replacement dormer windows are manufactured with a variety of framing options. Aluminum and vinyl dormer windows are a relatively inexpensive replacement window frame alternative which can be well sealed. They do not require maintenance. Windows with the newest grades of aluminum are suggested to reduce condensation and moisture build-up. Composite and fiberglass frames are strong and durable window frames which do not require any maintenance after installation. They are strong enough to support multi-pane windows. Wood windows are preferred by many homeowners because of their traditional appearance but the exterior of a wood frames requires maintenance to prevent rot and warping. Wood-clad windows address this problem by cladding the exterior wood frame with treated aluminum or vinyl cladding.
Dormer windows with multi-panes and a Low-E coating provide the maximum protection for the replacement window panes. The low-e coating also prevents items within the dormer from fading from the glare of the sun.
Operating dormer windows come with screens and operating hardware, including a built-in locking system.