Retrofit Windows

http://www.homeprohub.com/blog/new-construction-vs-retrofit-windows-understanding-the-differences/

{{Infobox
|title = Retrofit Window 
|image        = [[File:Space holder.jpg|215px|alt=Block Glass Windows]]
|header5 = Other Names
|data6   = Replacement Retrofit Window 
|header7 = Description:
|data8   = Replacement windows which do utilize the original window frame}}

Retrofit windows are installed on top of the original window frame, reducing the time and expense of replacing windows during a remodeling project.

== Retrofit Window ==
Retrofit windows are replacement windows that do not require structural modifications. They are installed within the existing window frame and do not alter the existing window weather seal or the building’s exterior. During a retrofit installation, the existing glass and/or sash is removed and a replacement window is installed over the existing frame. Homeowners who are replacing a window with another window of exactly the same size may choose to purchase a retrofit window in place of a new construction window which includes the window frame. 

=== Benefits ===
Retrofit windows are appreciated by many homeowners for a variety of reasons. They are generally a less expensive replacement window alternative than a new construction window. Installation of a retrofit window is frequently easier and faster than installation of a new construction window. A retrofit window installation will not damage the home's exterior finish and the homeowner will not need to paint the room's interior after the installation.

Some homeowners prefer the look of retrofit windows. These replacement windows tend to feature more white trim than the new construction window counterpart.

Retrofit windows offer all of the positive energy efficiency gains that a new construction replacement window offers. Installation of a retrofit window will leave the frame's moisture barrier undisturbed to ensure that a window that did not leak before the retrofit installation will not leak after the installation. 

Retrofit windows cost less to purchase and less to install but they increase the home's value by the same amount as a full new construction window offers. Retrofit window installation technology is now a proven technology. 

=== Types of Retrofit Windows ===
The window industry developed retrofit windows as replacement window alternative that cuts costs and labor, making replacement windows a viable option for all homeowners regardless of taste or budget. There are two main types of replacement retrofit windows:

==== Flush Fin ====
Flush Fin retrofit windows are used with aluminum windows which have stucco home exteriors. These windows, also called "Z-bar" windows are installed in the original aluminum frame, ensuring that the stucco siding is not damaged during installation. 

==== Block Frame ====
Block frame replacement windows are used in sites where wood windows are in place and are surrounded by an aluminum siding or brick exterior. In a block frame installation, also called an "insert" replacement window, the nail fin is removed before the retrofit window's installation and the studs are checked to make sure that there has been no damage to the studs. Proper insulation and flashing must also be present for a block frame replacement window to be effective. 

=== Quality Retrofit Window ===
When investigating the options for a retrofit window the homeowner should check that the replacement retrofit window carries the seal of the National Fenestration Rating council (NFRC). The NFRC rates and labels the energy performance of replacement retrofit windows as well as doors and skylights. 

Industry experts also suggest that the homeowner make sure that the retrofit window includes matching color on all of its components and that the metal lock components fit together properly. In addition, they recommend that the replacement window have heat-welded joints as opposed to a mechanical fastening in which the window sash and frame is sealed with caulk, screws or brackets. Heat-welded joints are more durable and provide better thermal insulation capabilities. 

=== Framing Materials ===
Retrofit replacement windows are available in a variety of framing materials which allow homeowners to select the framing matter that fits their visions of their home design as well as their budget and thermal insulation needs. These framing elements include fiberglass frames, vinyl frames, aluminum frames, wood and wood clad frames and composite frames. 

==== Fiberglass Frames ====
Fiberglass frames for retrofit replacement windows are a relatively new window framing alternative. They are light, strong and durable and provide excellent insulating qualities. They do not expand and contract with heat and cold in the same way as some other framing materials such as the older grades of aluminum. Fiberglass is a more expensive window frame alternative though many homeowners appreciate its durability and the fact that fiberglass frames do not require any sort of maintenance after installation

==== Vinyl Frames ====
New retrofit replacement vinyl windows include a polyvinyl chloride (PVC) which make vinyl windows a high-quality product that competes favorably with other window framing materials. Vinyl frames do not conduct heat which adds to the frame's insulating value. Vinyl window frames are hollow and include multiple chambers to add strength. They provide good insulating capacities by trapping air which slows the transfer of heat. Vinyl is more sensitive to temperature variations than other window materials so most window manufacturers do not include dark colors as vinyl frame options.

==== Aluminum Frames ====
Aluminum frames are a low cost retrofit window alternative. Aluminum frames offer good noise abatement properties along with a durable maintenance-free window frame. Older grades of aluminum were problematic insulators as moisture would build up on the aluminum frame interior as the frame conducted the cold from the outside. Today's aluminum frames offer better insulating capabilities. Many aluminum frames feature Energy Star ratings as a good insulating frame option. 

==== Wood and Wood Clad Frames ====
Wood frame and vinyl window frames now cover over 70% of the residential window market. Wood frame retrofit windows are a popular window alternative because they install easily into an existing wood frame and offer an attractive interior appearance. Wood frame windows can warp or rot if they are not painted or varnished annually. Today new lines of aluminum clad replacement wood windows solve this problem by including a treated aluminum cladding on the exterior frame of a wood window. This ensures that the exterior frame will be a good insulator and will provide a durable and maintenance free window while featuring an interior frame which presents the type of wood frame that many homeowners appreciate.

==== Composite Windows ====
Composite windows offer an energy efficient framing alternative for retrofit replacement windows. The process of creating a composite window frame involves using a hybrid of materials to manufacture the framing material. Composite frames include those with a blend of wood chips or recycled plastic, a fiberglass frame with interior wood cladding, a wood frame with aluminum cladding or vinyl frames that have interior wood veneers. Composite retrofit windows are available in a variety of colors and require no maintenance. The price of a composite window will vary depending on the composite materials used. 
 
=== Retrofit Window Types ===
Customers may find replacement retrofit windows in a variety of styles including fixed frames and picture windows, double hung windows, sliding windows, casement windows, awning and hopper windows, bay and bow windows and more. Some of the most popular retrofit replacement windows include operable windows which are both functional and attractive. 

==== Single Hung and Double Hung Retrofit Windows ====
Single hung and double hung retrofit windows are vertically elongated windows which fit into large window openings. They are manufactured with two sashes. The lower sash of a single hung window can be moved vertically within the window frame while both sashes of a double hung may be moved vertically within the frame. 
==== Sliding Retrofit Windows ====
Sliding and gliding retrofit replacement windows are horizontally elongated windows which present two sashes. Sliding windows include options for one or both sashes to slide horizontally which open or close the window. 

==== Casement Retrofit Windows ====
Casement replacement retrofit windows encompass a wide range of sizes. The hinges of a casement window are located along the side sash, allowing the casement window to swing inward or outward, depending on the location of the hinge. Casement windows are available as crank-in/crank-out windows or as push-in/push-out windows. 

==== Bay and Bow Retrofit Windows ====
Bay and bow retrofit windows are combinations of three or more non-operable or operable window sections which project outward from a room in an arc design. Homeowners may install one type of window for all window bay or bow window sections or combine two different types of windows into a bow or bay window. A bay or bow retrofit window may be constructed using a range of combinations. Bay or bow window combinations include using a picture window section for the middle window and casement or double hung windows on the sides, installing fixed-glass windows for the side windows with a double-casement window as the center window or using double-hung windows for all window sections. Other bay and bow retrofit replacement window options are also available. 

==== Awning and Hopper Retrofit Windows ====
Awning and hopper retrofit replacement windows increase the ventilation in a room. They can be installed in a small wall opening. Hinges on the top of the window frame (hopper) or the bottom of the window frame (awning) ensure that the opening angle increases privacy while allowing for adequate air flow into the room.  Hopper and awning windows may be installed in small openings on their own or may be installed on the top or bottom of a picture, double hung or casement window as an enhancement to the window's appearance and an option for increasing ventilation. 
=== Energy Efficiency ===  
Homeowners who are investigating available retrofit options must include the level of the replacement window's energy efficiency in their calculations. One reliable tool is the retrofit window's U-Rating. The U-Rating is the ranking which indicates the level of thermal insulation that the window offers. Retrofit windows which provide good insulation are those which have a U-Rating of 30 or less. These are frequently a more expensive window purchase but a homeowner can recoup the additional costs involved in the window's purchase and installation within four years of the window's installation through savings in heating and cooling costs that the window presents. In addition, rebates and tax credits are offered to homeowners who remodel with Energy Star rated windows. Energy Star windows reduce energy costs by 7-15 percent.  

=== Retrofit Glazing Alternatives ===
In addition to the replacement window's framing materials, the U-Rating takes the retrofit window's glazing into consideration in calculating the window's energy efficiency. 

==== Multi-Pane Windows ====
Fiberglass, vinyl, aluminum, composite and wood frame retrofit window manufacturers offer multi-pane windows as an option for glazing insulation. Including double or triple panes in the retrofit window's frames helps the interior glass stay warmer and reduces energy costs. The United States Department of Energy estimates that energy efficient windows, including those which have multi-panes, contribute to anywhere from $200 - $600 in annual reduced energy costs (differences are due to differing climates throughout the United States).

==== Gas Insulation ====
Many window manufacturers insulate the area between the panes of a multi-pane retrofit window with insulating krypton or argon gas. These gases further insulate a replacement window's glazing capabilities. 

==== Low-E Coating ====
Some window manufacturers offer an additional glazing coating which works as a kind of "sunscreen" for the window by reducing the “heat gain” into the home by 30% - 50%. This Low-E (Low-Emissivity) coating adds an invisible layer of metallic oxide to the glass and provides an additional barrier which helps to control heat transfer caused by the sun's rays. 

=== Accessories ===
Window manufacturers offer a wide range of retrofit window accessories, both standard and special order, to replacement orders. These accessories include window screens and operating hardware (cranks, locks, handles) which are standard additions to an operable window order.  Window hardware generally comes in hard plastic though a customer may upgrade the order to include bronze or brass hardware. 

In addition, grilles may be included on a retrofit window order. A homeowner can request that the factory install the grilles between the window's panes or include them as clip-on grilles which can be added to the windows or removed at will.