Great windows and doors are essential for a quality build. In this series, Ade takes you through some of the essential terminology to ensure that when you buy windows and doors for your next project, you won’t be baffled by the BS.
Plumb (and Square)
Of course, you know what this means! But if everyone did, why are we called out to so many issues created by windows and doors that are not fitted ‘plumb and square’?
Here’s what they mean:
Plumb: This refers to the vertical alignment of the window. A window is “plumb” when its sides are perfectly vertical, meaning the frame is not leaning to one side or the other. To check for plumbness, an installer would use a level to ensure that the vertical lines of the window frame are straight.
Square: This refers to ensuring that all the corners of the window frame form perfect 90-degree angles. A window is “square” when all the sides and corners are aligned correctly, so the frame is not twisted or distorted. To check if a window is square, installers might measure the diagonals from corner to corner- if both diagonals are equal, the window is square. Ensuring that the window is both plumb and square is crucial for proper operation, as it helps avoid problems like drafts, leaks, and difficulty in opening or closing the window.
Reveal (depth)
The “reveal” refers to the visible portion of a wall or opening that is exposed when a door or window is installed. It is the section of the wall that surrounds the door or window frame, typically showing the thickness of the wall and any materials or finishes.
Sightline
This refers to the unobstructed line of sight through the window. It describes the view a person has through the glass and how much of the frame or other structural elements block that view. Slim sightlines generally mean that the window has minimal framing, providing a clearer, wider view outside. Thick sightlines would indicate more visible frame, which may reduce the amount of the view you can see.
Thermal Break
A layer of insulating material placed between the interior and exterior parts of a window frame to reduce heat transfer. It is typically used in metal window frames, such as aluminium, which conduct heat more readily than materials like wood or uPVC. Without it, such frames could not provide the thermal performance required by Building Regulations.
Transom
A transom is a horizontal beam or bar located across the top of a window or door. In the context of windows and doors, the term can also refer to the window or panel installed above a door or another window.
Twist
This refers to a window frame or door that is twisted or warped when installed. It is caused invariably by poor installation (see ‘plumb’ and ‘square’ above!). The window or door will simply not function correctly when this happens.
Toe and Heel
When you install a window or door, the weight of the glass or door panel can cause it to drop or sag over time. To prevent this, small plastic wedges are inserted diagonally (from the bottom corner of the hinge side to the top corner of the opposite side) between the frame and the glass or panel. Although this sounds like a simple task it is remarkable how many call-backs are received because this is not done correctly.
U-value
A measure of thermal transmittance or the rate at which heat is transferred through a building element, such as a window. A lower U-value indicates better insulating properties.
(Trickle) Vents
Small ventilation openings built into window frames to allow a continuous flow of fresh air into a room. They help to reduce condensation and improve indoor air quality without needing to open the windows fully. Required by law in most installations.
Warm Edge Technology
Warm edge is so called as it insulates the edge of the sealed unit where most heat is lost. Often referred to as a ‘thermal break’, it slows the heat loss across the edge seal/spacer matrix and therefore improves insulation. Warm edge lowers the U-values of windows.
Warp
Warp is the deformation of a material such as wood, metal or uPVC where it bends or loses its original shape. In windows, this can cause frames or sashes to become misaligned or difficult to operate.
Wow!
The expression that you want your customers to use when they first see the windows and doors that you have helped them choose for their project. Great windows and doors will make a project!
X-Factor
I added this one because whilst it is not exclusively a term applied to windows and doors, it is still highly relevant because it is possible to lift or lower the appearance and performance of a building by the quality of the fenestration.
In the context of windows and doors, the X Factor refers to unique or standout qualities that set installations apart from others. It could describe a special feature, design innovation, or performance attribute that makes a particular window or door more desirable. For example, it might be:
Energy efficiency: Exceptional insulation, glazing, or frame materials that significantly reduce energy loss.
Aesthetic appeal: A distinctive design or finish that enhances the look of a home.
Durability: Superior materials or construction that make the product more long-lasting and weather-resistant.
Security features: Advanced locking mechanisms or reinforced glass that provide higher levels of protection.
Ease of use: Windows and doors that are particularly easy to open, close, clean, or maintain.
Yield Point
The point at which a material, such as a window frame, begins to deform permanently under stress. It’s an important factor in determining the durability and strength of materials used in windows.
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