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Get Smart About Windows & Doors

By Gates Dearen
You may have heard it said that today, especially with the popularity and easy access to the Internet, we live in the “Age of Information.”  Have a question about something? Want to learn a new skill? Embark on a DIY project? Make an intelligent buying decision? Save money? Chances are, by searching, or “googling” on almost any subject imaginable, you can find a wide range of highly useful information, all readily available on your PC, smart phone or device.

The fact is, a well-informed potential buyer is better able to understand, discuss and consider the various features of, and options pertaining to a particular product. There are advantages for the customer and oftentimes, seller:
  • Reduction in shopping time
  • Better concept of wants vs. needs
  • Cost savings
  • More informed buying decision
  • Less prone to being swayed by hype or misinformation
  • Less second guessing after the purchase
As you may recall in one of our previous blogs entitled, “Home Security; What Part do Your Doors Play?” we considered the various security components that differ from design to design, manufacturer to manufacturer; with certain design elements and components offering more protection than others. 

The same is true with windows and doors. If you’re considering replacing your current front door, patio door or windows, or are building a new home and are in need of purchasing new doors and windows, it’s helpful to understand the terminology so you can understand and speak the lingo.

Courtesy of
Below is a fairly comprehensive glossary of terms, concepts and key measurements and ratings used in the door and glass, mostly pertaining to windows/glass.  Note: an italicized word appearing in a definition means that particular term is also defined in this glossary.

American Architectural Manufacturers Association. A national trade association that establishes voluntary standards for the window and door industry.

To provide an extremely hard, non-corrosive oxide film on the surface of aluminum (i.e., a front or non-patio
door), through an electrolytic process. Anodic coatings may be transparent, or varying shades of silver, grey, brown, or other colors may be incorporated by the use of dyes.
An inert, colorless, and harmless gas used instead of air in sealed spaces between panes of glass, which is used to increase insulation. Argon is less conductive to heat than air.  It is injected in the airspace of an insulating unit, to improve energy efficiency.

Awning Window
A type of window with a top-hinged sash that swings out at the bottom, letting in fresh air while keeping rain out.

A mechanical device used in vertically operating windows that counter-balances the weight of the sash during opening and closing (see image at left).

1) A strip of metal, vinyl, or wood used around the periphery of a pane of glass to secure it in a frame or sash.
2) A strip of sealant, such as caulking or glazing compound used with windows.

To shim, level and plumb windows in required position.

Casement Window
A type of window with a side-hinged sash that opens like a door ― the best window for catching breezes and crosswinds. The sashes are usually operated by means of roto-operators or handles.
Double Hung Window
A type of window that has an upper, outside sash that slides down, and a lower, inside sash that slides up.  A vertical operating window consisting of two sashes of glass operating in a rectangular frame, both the upper and lower halves can be slid up and down and usually use a counter balance mechanism to hold the sash in place.

Interior cladding with panels of gypsum board, fiber board or plywood - providing for a dry operation as opposed to wet plaster.

A measure of an object’s ability to emit long-wave infrared radiation or room temperature radiant heat energy. Emissivity varies from 0 (no emitted infrared) to 1 (100% emitted infrared). The lower the emissivity, the lower the resultant U-value (see illustration at right). 

The placement and arrangement of the windows and doors in a building.

Consists of a head, jambs, and a sill to form an opening into which SASH or door panels fit. An assembly of structural elements that surround and support the sash, ventilators, doors, panels or glazing which is installed into an opening in the building envelope or wall.

A mechanical seal that fills the space between two or more mating surfaces, generally to prevent leakage from, or between the joined objects while under compression. Gaskets allow "less-than-perfect" mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced by cutting from sheet materials (see photo at left).

The installation of glass into a window or door sash

Glazing Bead
A molding or stop along the inside perimeter of the frame that assists in holding glass in place.
Decorative inserts for windows or door glazing that adds a traditional touch ― available in fixed or removable inserts.

The main horizontal member forming the top of the window or door frame (see diagram at right).

A device on which doors or windows may turn or swing, to open and close.

Horizontal Sliding Window
A window where the movable panels slide horizontally. These windows consist of one or more horizontally operable sashes in a sealing frame.

Insulating Glass
Two or more pieces of glass spaced apart and sealed to form a single-glazed unit with an air space between. Heat transmission through this type of glass may be as low as half of that without such an air space.

A set of meeting rails or meeting stiles that contains a provision for each of the rails or stiles to physically engage one another over their entire length.

Vertical, or side members of the window’s or door’s main frame.

Laminated Glass
Two or more sheets of glass with an inner layer of transparent plastic to which the glass adheres if broken. This process produces glass four times more impact resistant than non-tempered glass. Used for overhead applications, safety glazing, and sound reduction (see illustration at left).

Lift Rail 
A rail in a vertical window provided with an operator to raise and lower the operable sash

The device on a window or door that secures it in a closed position.

Sputtered Low E Glazing. Sputtered coatings are multilayered coatings that are typically comprised of metals, metal oxides, and metal nitrides. These materials are deposited on glass or plastic film in a vacuum chamber in a process called physical vapor deposition. Sputtered coatings have emissivity as low as 0.02 which are substantially lower than those for pyrolitic coatings.

Low E Glass
Courtesy of
Low-emissivity glass with a transparent coating which acts as a thermal mirror ―used to increase a window’s insulating value, block or increase heat flow, and reduce fading.  The “E” is short for emissivity, specifically thermal emissivity.  Low-emissivity windows and doors cause heat to be reflected off, rather than allowing it to collect and seep through, or be emitted into the home (see illustration at left).

Marine-Type Glazing
A glazing system that begins by wrapping the full perimeter of the glass unit with a soft vinyl channel, which serves to cushion the glass, as well as provide positive protection from water. Marine-type glazing is typically found on high quality window products.

Meeting Rail
A rail that overlaps another rail. The part of a sliding glass door or a sliding window where two panels meet and create a weather barrier.

An intermediate-connecting member used as a means to “join” two or more window products together in a single rough opening.

Muntin Bar
A small bar that divides window or door glass (see photo at right).

Nailing Fin
An integral extension of a window frame that generally laps over the conventional stud construction and through which nails are driven to secure the frame in place.
National Fenestration Rating Council: Measures and compares the energy component of windows and doors.

Obscure Glass
Mainly used for decoration, diffusion, or privacy. The design is pressed into the glass during the rolling process. There are many patterns available. 

A framed sheet of glass.

A part of a fenestration product, composed of a lite of glass and surrounded by a frame. Panels can be fixed in place or be movable (see photo at left).

A horizontal surrounding edge member of a sash, ventilator, or panel.

Framing system consisting of one or two aluminum extrusions used to contain a window or door frame, head and/or jambs in a masonry type opening. Allows and compensates for deflection and inconsistencies in the openings.

A window opening device that has a handle used to crank open a window.

The portion of a window that includes the glass and the framing sections, which are directly attached to the glass. Normally, the moving segment of a window, although sashes are sometimes fixed. Not to be confused with the main frame into which the sash sections are fitted (see illustration at right).

A product used with a window or door, consisting of a four-sided frame surrounding a mesh of wire or plastic material used to keep out insects. The screen can be fixed in place or it can be rolled side-to-side as on a sliding glass door.

The main horizontal member forming the bottom of the frame of a window or door.

Single Glazing
The use of single thickness of glass in a window or door.
Single Hung Window
Single hung windows are vertically operating windows in which the sash weight is offset by a counterbalancing mechanism mounted in the window. The single hung window features a stationary top and a movable bottom half. One or more locking devices are furnished to secure the sash in the closed position (see photo at left).

Slider Window
A slider window may have one or two movable panes of glass. Whatever the type, the windows slide horizontally in the frame.

Sliding Glass Door Sliding glass doors consist of one or more pieces of glass contained in panels, which are contained within an overall frame designed so that one or more panels can move in a horizontal direction. Panels can all sliding, or some may be fixed. Panels lock or interlock with each other or contact a jamb member enabling a secure lock. Doors shall be designed and assembled so that panel to panel contact between horizontal members moving relative to each other does not occur.

In glazing, small blocks of neoprene, nylon, or other materials are placed on both sides of the edges of glass during its installation to center it in the glazing channel to maintain uniform width of sealant bands and prevent excessive sealant distortion under lateral loading.

The upright or vertical surrounding edge members of any sash, ventilator, or panel
Tempered Glass
The glass is reheated to right below its melting point, and then suddenly cooled. When shattered, it breaks into small pieces. It is approximately five times stronger than standard annealed glass. It cannot be re-cut after tempering.

Tinted Glass
A mineral admixture is incorporated in the glass, resulting in a degree of tinting. Any tinting reduces both visual and radiant transmittance.  

U Values
A measure of heat loss in a building component such as a wall, floor or roof. It can also be referred to as an “overall heat transfer co-efficient” that measures how well parts of a building transfer heat. The higher the U value, the worse the thermal performance of the building envelope. A low U value usually indicates high levels of insulation.

The invisible rays of the light spectrum that are outside of the visible spectrum at its violet end. UV rays are found in everyday sunlight and can cause fading or chalking of dark paint finishes (see diagram at left).
Polyvinyl chloride (PVC) material that can be either rigid or flexible, used in glazing channels and weathering of both windows and doors.

Warm Edge Spacers
Insulating spacers used to seal panes of glass in the manufacture of insulated glass units, thereby lessening edge conductivity for improved window energy performance and reduced condensation problems.

Weather Stripping
Thin sections of material used to prevent air leakage around operable windows and doors ― usually with foam gaskets, metal strips, or vinyl (see photo at right).

An opening constructed in a wall or roof and functioning to admit light or air to an enclosure, usually framed and spanned with glass mounted to permit opening and closing.

In this article, I’ve provided some of the key definitions, concepts and design features related to doors, sliding glass doors and windows. We discussed why it’s important for consumers to have a working knowledge of these terms and concepts in order to make a more informed buying decision.

If you would like to receive an official factory authorized 30% discount coupon for your next window replacement purchase, print out this article with the coupon on it  and bring it with you when visiting HomeRite.

If you found this article helpful, please forward it to others. If have a comment or question please post it in the “Comment” section below.  As always, thanks for taking the time to visit our blog. 

Gates Dearen is the co-owner of HomeRite Windows and Doors in Jacksonville, Florida. Owners Dearen and Richard Walden have been serving the building products industry in Florida for over 25 years. They know the products, the industry, the market and what adds great value to a home. Their approach is somewhat different than others.  They strive to match the homeowner with the right windows and doors for their home and budget.  They know that some home improvement projects can be a hassle.  They strive to make the process pleasant with first-rate, energy efficient products; affordable prices; and expert, award-wining installers that employ the best practices and who respect your home as if it were their own.


  1. Great information. This really helped me understand all the window jargon that went over my head before.

  2. I'd no idea there was so much to windows. Now it's "plane" as day.

  3. Basically it comes down to two choices: Either save now or pay later.

  4. I have just installed iStripper, so I can watch the sexiest virtual strippers on my taskbar.

  5. Very good read, indeed - many ppl buy the windows and doors without taking a second look at them or knowing what actually lies within the system... I prefer Aluplast doors for my personal and professional choices.

    Aikon Distribution