Glossary of Window and Door Terms

Ever wondered what AS stands for, what window bars are, or what on earth a hopper, jamb or a parliament hinge is? Thought about installing new glass doors in your home, but aren’t sure what kind of flashing, annealing, mullions or transoms are best to use? The world of windows and door manufacturing, like any specialist industry, has its own set of technical terms which can be confusing to get your head around. To make things easier for you, we’ve put together this helpful glossary of terms. You can even print it out and keep it with you when you’re shopping around for new aluminium windows and doors for your home.


Aluminum angle

Right-angled or flat aluminum extrusion, powder-coated to match the window or door. Available in various sizes it is used as a finishing solution during installation.

Aluminium anodising

Aluminium anodising is a type of coating added to aluminium by means of an electrochemical process. Anodising increases the durability and corrosion-resistance of aluminum, as it increases the thickness of the oxide layer on the surface of the metal. Windows and doors constructed with aluminium frames should be anodised to ensure that they withstand outdoor weather conditions.

Architrave – Internal and external

Architraves refer to the trim around door and window frames. As well as having an aesthetic and design function, they also hide the point where window and door jambs fit into the wall. Architraves can also be used in wall openings and doorways in which no doors or windows are installed (such as internal archways between rooms).

Annealed Glass

Annealed glass is a type of float glass which has been slowly cooled in order to relieve internal stresses in the material, and hence reduce the risk of the glass shattering or cracking when the it undergoes small temperature changes or mechanical shocks. Using annealed glass for glass windows and doors in the home is important, as they need to withstand everyday opening and closing, as well as constant outdoor temperature fluctuations and weather conditions.


AS stands for Australian Standard. Australian Standards are national benchmarks for products and services which ensure efficiency, safety, high quality, and most of all, suitability to withstand Australia’s particular climate conditions. Products which adhere to these strict high standards mean that they have undergone rigorous testing and have been proven to be safe, durable, and suitable for use in the home. All of BetaView’s products adhere to Australian Standards, meaning that you’re always getting a top-quality product in your home.


AWA is the Australian Window Association. The Association is comprised of over 500 window manufacturers and industry suppliers throughout Australia, all of whom manufacture and sell products which adhere to Australian Standards. Betaview is a member of AWA.

Awning Window

An awning window is hinged at the top of the glass, while the bottom of the window swings outwards. Awning windows are configured only open to a fixed degree, making them perfect for leaving open in the rain. Awning windows are also ideal for helping to prevent accidents in homes with children.



Bars, also sometimes called glazing bars, are bars that are applied on top of the glass in larger windows and doors. Their purpose is mainly aesthetic, as they visually separate a large pane of glass into smaller sections.

Bifold Door (bi-fold folding door)

Bifold doors are made up of multiple panels (usually two or more) with hinges in between each panel to allow the doors to fold away and stack on top of each other when fully openened. Bifold doors are great for making the most out of an entire door opening as a thoroughfare, as there are no fixed sections of glass which cannot be opened.

Bushfire Attack

Bushfire Attack refers to the amount of ember attack, radiant heat, and direct flame contact that a building can be exposed to during a bushfire. Different types of Bushfire Attack can cause varying defrees of damage to a building.

Bushfire Attack Level (BAL)

BAL stands for Bushfire Attack Level, and is a rating system developed under Australian Standard 3959 which refers to different levels of bushfire damage that a building may be exposed to during a bushfire. The BAL is split into 6 categories of varying severity, including (from lowest severity to highest) BAL-LOW, BAL-12.5, BAL-19, BAL29, BAL-40 and BAL-FZ. All of Betaview’s aluminium windows and doors have been certified and proven to withstand a BAL of up to 40.


Casement Window

A casement window refers to any type of window which is attached to its frame on one side by a hinge, ether at the top (awning window), side (regular hinged window), or at the bottom (hopper window). Casement windows are ideal if you want to have windows in your home that only open to a certain degree, either for safety or aesthetic purposes.

Check measure

The check measure is a meeting between the customer and the Installation Supervisor. Final measurements are taken ahead of production and all details are finalised, including colour and requirements for the installation work.


The Commercial range is a small suite of commercial grade windows and doors. Typically, heavier than regular residential windows and doors. Suitable for demanding architectural projects with large openings.


Diamond grille

Security screen with regular diamond grille design.

Double Glazed Unit (also known as Insulated Glass Unit – IGU)

Double Glazed Units refer to panels made of two panes of glass which are separated by an airtight space in between them. The space in between the glass is pressurised to create tension, which toughens the glass and makes it more resistant to breakage, improves its energy efficiency. To avoid moisture vapour and water droplets forming in between the two panels of glass, a dessicant, or drying agent, is used in the space. Double Glazed Glass is the best performing, strongest and most energy-efficient and sound-insulating glass, making it perfect for use anywhere in the home.

Double Hung Window

Double hung windows are made up of two panels or sashes which move vertically up and down. The top panel opens downwards, while the bottom panel opens upwards. The opening movement is controlled by spring balances, making it easy to open and close the windows, and allows you to leave windows open as much or as little as you want.



Emissivity refers to the ability and effectiveness of a material in emitting any thermal radiation (i.e. heat) that it absorbs. The higher emissivity a window has, the more absorbed heat it emits. Low-e glass has the lowest emissivity of all glass types, due to a special coating on the surface of the glass. In this way, it helps keep rooms cooler in summer, and warmer in winter.


An extrusion refers to the aluminium components of a door or window. They can include the window frame, as well as any bars which are placed on a pane to visually separate the glass pane. If your home is short on space, choose window and door designs with minimum extrusions.


Fixed Lite

Fixed lites are a type of window which are fixed, and do not open. They are used for views, and also to allow more light into the home. They can be placed in a wall alone, or can be installed directly adjacent to functioning windows and doors to make them appear bigger, and to allow more light to enter the room.

Fixed Panel/Fixed Lite

A fixed panel or fixed lite is any panel in a window or door which does not open or close. Often they are installed around or beside operable windows and doors for aesthetic purposes, or to increase the amount of light entering a room, while keeping the operable part of a window or door to a certain desired size.

Flame Zone (FZ)

Flame Zone (FZ) is the highest BAL (Bushfire Attack Level) that buildings sustain. Flame Zone refers to direct exposure to flames, as well as ember attack and heat flux.


Window flashing is a plastic or metal strip of material which is installed around window jambs, designed to prevent water leakage into the surrounding wall. Windows which are not made completely watertight with effective flashing can let water seep into the inside of walls (particularly in wet and very windy weather conditions) potentially causing rot and other water damage over the long term.

French Doors/Hinged Doors

French doors, sometimes also referred to as hinged doors, are a type of door in which the two opening edges of the door are adjacent to each other. They can be configured to open inwards or outwards.



Glazing refers to the actual part of a wall or window which is made of glass. It can also refer to the way that a glass panel is constructed (eg. double glazing, triple glazing).

Grade A safety glass

Grade A Safety Glass is a type of glass which adheres to the highest safety requirements of Australian Standard 1288 (AS1288). High-traffic areas of a home, and areas that tend to be prone to accidents (such as large doorways which people may accidentally walk or fall through) are required to be fitted with this type of glass. Additionally, all glass in bathrooms (such as for windows and glass shower screens) should be fitted with Grade A Safety glass.


Heat Gain

Heat gain refers to the amount of heat which is transferred from the outside of a building to the inside, through vertical windows, doors and walls. When looking at glass windows and doors, it’s important to consider windows with a lower heat gain, as these will help rooms stay cooler in summer time.

Heat Loss

Heat loss refers to the transfer of heat from the inside to the outside of a building. Choosing a type of glass for your windows and doors that has a lower level of heat transfer will help keep heat in when it’s colder outside, and reduce your heating costs.

Heat Transfer

Heat transfer refers to the transfer of heat either into or out of a building, through the processes of radiation, convection and conduction. When choosing windows and doors for rooms you want to keep insulated, choose glass that has lower levels of heat transfer, to help keep the temperature in your home more constant, with less of a need to use heaters or airconditioning.


A highlite is a fixed panel or sash above a glass window or door, which may be operable or inoperable. It can be useful for when you want to let a little air into the home for ventilation, but don’t want to leave an entrance door open.

Hinged Doors

A hinged door is a traditional type of door which is hinged on one vertical side and can be opened inwards or outwards. Double hinged doors in which the opening edges are adjacent are known as French doors.


Insulating (or insulated) Glass

Insulating glass refers to any type of glass which is comprised of two or more panes with a completely sealed, airtight space in between each pane. This space may be filled with either dehydrated air, or an inert gas such as argon, which will further increase the energy efficiency of the glass. Double glazed windows are one example of insulated glass.

Invisi-Gard (security screen)

High performance security screen for windows and doors. 316 Marine Grade Stainless Steel Mesh with extruded aluminium perimeter framing.



Jambs are the upright vertical sections either side of a window or door opening.


Laminated Glass

Laminated glass is a type of glass which has a special layer inside it made of a type of plastic. If the pane of glass is broken, the shards adhere to this inner layer rather than falling onto the ground. Laminated glass can be an effective security measure against intruders entering your home, and is also ideal for use in areas of the home which are high-traffic and may be prone to breaking.

Low-E Glass

Low-E (Low Emissivity) is a type of glass that has a special energy efficient coating. This reduces the transfer of heat between the indoor and outdoor environments. Low-E glass is a great all-round option that helps increse the energy efficiency of your home both in summer and winter, providing a noticably improved level of comfort.

Low Lite

A low lite is a fixed pane of glass which is often placed below a window, usually for aesthetic, design, or safety purposes (for example, when you don’t want an operable window within easy reach of children).


Louvre windows are a type of window made up of a series of horizontal blades of glass which overlap each other when closed, and open to allow air to pass through the blades. They are usually controlled by a lever, and can be left open in light rain.



Safety motif. Subtle design added to doors to prevent accidents – legal requirement on glass doors.


A mullion is a vertical section between window units which visually and physically separates two windows from each other. Mullions can be purely aesthetic, or used to provide physical support for larger panes of glass.


Obscure Glass

Obscured glass is a type of textured glass which allows light to pass through, but makes the actual view through the glass blurry or distorted. Obscured glass is ideal for areas of the home which require more privacy, such as bathroom windows or in front entrance doors. Obscured glass can also be used in areas of the house where you want to let some light in, but where a clear view to the outdoors is not needed.


Patio Door

A patio door is any door which allows access to a patio, backyard, porch or balcony. Patio doors can be hinged doors, sliding doors, stacker doors, or French doors, and door style is usually determined by personal preference and space requirements.

Parliament Hinges

A parliament hinge is a type of flat hinge which sits flush with the door or window pane and the frame that it’s attached to. They allow doors to be opened a full 180 degrees, allowing the door or window to sit right against the wall, which is great for saving space.



BetaView’s residential (or essential) range is a range of standard aluminium windows and doors, which are available direct to all of our customers. All of our residential products adhere to Australian Standards and have a BAL-40 bushfire rating.


Safety Glass

Safety glass refers to any type of glass which has been treated in a way which reduces the risk of injury occuring if the glass is broken. The highest grade of safety glass is Grade A Safety glass.


A sash refers to the frame of the window which holds the pane of glass in place. This frame is placed inside the window frame that’s attached to the wall. Sash can also describe the part of the window which actually opens and closes.

Semi-Commercial (Signature)

Betaview’s semi-commercial (or signature) range refers to a premium range of commercial-grade aluminium windows and doors, which are designed specifically for residential application. Signature range is available direct to builders and architects for their projects.

Side Lite (or side light)

A sidelite refers to a small, narrow piece of glass which is fixed, and is often placed next to an operating window or door. Sidelites can be used for aesthetic purposes, or for letting more light into the home.


A sill refers to the bottom horizontal beam of a window frame, which supports the rest of the window. Sills can be the same width as the rest of the window frame, or can protrude outwards slightly in order to create a flat surface to place objects on, or if wide enough, to create a seating space (such as in bay windows).

Single Glazing

Single glazing refers to a pane which is simply made up of one sheet of glass. Single glazed glass is ideal for areas of the home which do not need any insulation, such as internal doors, shower screens, in kitchens or in balustrades.

Sliding Window

A sliding window is made up of one fixed pane of glass, and one moving pane which slides open horizontally over the fixed pane. Sliding windows are ideal if you don’t want any extruding glass window panes to take up any room inside or outside your home.

Solar Gain Heat Co-efficient (SHGC)

Solar Heat Gain Coefficient (SHGC) refers to how much solar radiation enters into a room through a window, and is represented as a number from 0 to 1. The lower the SHGC of a window, the less sunlight it allows into a room, and the more energy efficient it is.

Sump Sill

A sump sill is a specially designed window sill which allows water to drain to the outside of the building. It’s most often used in areas where extra water resistance and protection is needed.



A transom is a horizontal beam which separates a door or window from the lite (fixed window pane) above it. Transoms are used to add support when you want to add another pane of glass above a door to allow more light into the room, or for purely aesthetic reasons.

Triple lock – Security door

A triple lock is a type of security lock which secures a door shut in three points when the key is turned, rather than just one. It provides an extra layer of security, as it is harder to tamper with and force open than single locks.



U value describes the ability of a material to insulate against heat loss and heat gain between inside and outdoor areas of the home. The lower the U value, the less heat that surface allows heat to pass through. Whereas SHGC refers only to heat produced by the sun, U value refers to temperature from all sources (including the sun). Windows with a lower U value will also keep rooms warmer when the weather is cool, as they allow less heat to escape from inside a room.

Uni-bolt (bifold and french doors).

A uni-bolt is a type of handle used on bi-fold doors and windows to latch and lock the panels in place. This is not used on the main door, which instead has a regular handle positioned for easy access.


Vent Lock

A secure locking mechanism used to hold a window panel marginally open for the benefit of ventiallation.

Visible Transmittance (VT)

Visible Transmittance (VT) refers to the amount of visible light which can pass through a piece of glass. The VT of a piece of glass is represented as a number between 0 and 1 – the higher the number the more light which can be transmitted through a pane. The VT of a pane of glass can be altered by things like the type of glazing, and any coatings on the glass (such as tinting).


Weather Stripping

Weather stripping refers to material which is placed over the openings, ventings or cracks of window and door units to prevent air and water coming through. Weather stripping helps to make your windows and doors more energy efficient, as it prevents cool air escaping the house in summer, and warm air escaping the house in winter.


WERS refers to the Windows Energy Rating Scheme. WERS is a system developed by the Australian Window Association (AWA) and measures how energy efficient windows are, based on their cooling and heating performance. Both a window’s heating and cooling performance are individually rated with a star rating system on a scale of 0 to 10 stars – the more stars, the better the energy efficiency of the window. Windows that have been rated will display the WERS logo.