Glossary

The British Fenestration Rating Council (BFRC) Window Energy Ratings offer a clear way to show consumers the energy rating of a particular product. The familiar coloured ‘rainbow’ label is similar to those you will see on refrigerators and other electrical appliances, with A++ the most energy efficient. 

The list of independent testing and quality standards the Liniar range has been subjected to and passed, offering additional peace of mind to purchasers.

Liniar offers a range of ancilliary products including cills, trims, reinforcements and structural couplings such as butt joints and bay pole assemblies.

Additional security features to prevent a bump key being used to gain unlawful entry to your property.

Additional security features to prevent external sliding doors being lifted or moved.

Additional security features to prevent burglars snapping the lock’s cylinder to gain unlawful access to your property.

Guidelines set out for different areas of construction to help specifiers and contractors meet Building Regulation standards.

uPVC window manufacturers that have been approved by Liniar, having passed a series of tests to ensure products are manufactured to our exacting high standards, using only Liniar-approved parts.

Also called Georgian bars, they offer the illusion of small, individual panes of glass within a larger pane. Foiled to match your window for a seamless appearance.

The handrail and picket system used in conjunction with Liniar uPVC decking, offering an attractive, safe and strong finish for verandahs and decking installations.

A Liniar bay pole assembly is required for the correct installation of bay and bow windows.

The British Board of Agrement is the UK’s main organisation for construction products and installers.  For a product to approved by BBA it has to be subjected to rigorous tests to ensure it complies with building regulations.

The uPVC  glazing bead  which securely clips in around a window’s glazing unit, holding the glass in place and providing weather tight seal.

Also known as the Chamfered style of window profile.

The British Fenestration Rating Council is the premier UK authority for independently verified ratings of energy efficient windows and energy efficient doors.

A door consisting of anywhere between 2 and 7 panes which slide and fold back on themselves – creating a full width opening.

British Standards Institute - a verified, independent source of testing and certifications.

Liniar’s patented design, the bubble gasket is the black rubber seal you see around the window frame. This is co-extruded onto the uPVC frame, creating a  continuous weather-tight seal.

Government-set criteria that all new building projects must comply with – including energy efficiency, security and weather performance.

A standard term for windows which are top or side hung and which open outwards. Liniar uPVC casement windows are available in a wide variety of styles, with bespoke sizes for your project.

All complete, finished products made from Liniar profiles should be supplied with CE Marking, which is the manufacturer’s declaration that the window or door meets the requirements of the applicable European directives.

A style of window profile, or frame, offering a bevelled edge which looks flat, rather than curved (sculptured). Often used to give a contemporary appearance, or to resemble the old putty lines found on traditional windows.

Also known as sill, the external uPVC cill offers an attractive finish to a window and helps to prevent rainwater dripping directly onto the brickwork underneath. Internal cills are usually made from window board and can be painted to match internal décor.

A process where the gasket, or seal, is seamlessly manufactured onto the window profile as part of the extrusion process. This process is known as “co-extrusion”.

A door made from a combination of materials, designed to offer the appearance and strength of a timber door with the thermal and maintenance benefits of uPVC.

A sun room or garden room attached to a dwelling, consisting of at least 50% translucent materials within the walls and 75% of the roof area.

A built-in feature of patio doors, to prevent the sliding pane crashing into the frame when the door is fully opened. Unlike other patio systems, Liniar’s ModLok patio has hidden crash stops for better aesthetics.

A process of durability testing where the product is subjected to repeated cycles of the same motion. The Liniar ModLok bi-fold and patio door systems have been cyclic tested by our in-house articulated robot.

Glazing units formulated from two panes of glass filled with either air or argon – vastly more thermally efficient than the original single glazed panels used in years gone by.

The sash (the part of the window that opens) is sealed on the exterior side and interior side and sits flush in a groove in the window frame. Offering higher thermal efficiency.

Part of a residential or composite door, the drip bar helps to deflect rainwater away from the door and prevent water pooling.

A sash that does not open, usually included to enhance the appearance or symmetry of a window.

“Using less energy to provide the same level of service” is a general definition. In our industry that would be using less energy to keep your home at the desired comfortable heating level.

Liniar’s 6-chambered energy efficient window profile, available on many products in the range to offer even better U-values.

The manufacturing process of making plastic products – raw material is heated and pushed through bespoke tooling to produce specific, detailed shapes before being cooled and foiled to add optional ranges of colour.

Often a L-shaped board used in conjunction with soffits to help the transition between a buildings roof and wall, and to create an area able to accept guttering components.

The term for windows where the sash fits flush within the frame. This style was developed to mimic pre-1932 traditional timber windows and is ideal for conservation areas and modern developments alike.

The process of mechanically covering the uPVC profile with an attractive non-peel coloured finish, giving it a totally different appearance.

A pair of doors with glass panes extending for most of their length. Available with side lights for wider apertures.

Similar to a casement window, however both panes are side hung and open outwards with the mullion attached to one side, providing unrestricted views and excellent means of fire escape.

Ensures that all new homes built from 2025 will produce 75-80% less carbon emissions. 

The black weather-tight seal around your windows and doors. Liniar’s unique patented bubble gasket has been specially developed from scratch to give excellent weather performance.

Also called astragal bars, they offer the illusion of small, individual panes of glass within a larger pane. Optionally foiled to match your window for a seamless appearance.

The Glass and Glazing Federation is the main representative organisation for companies involved in the manufacture of products and services for all types of glazing.

Developed by Liniar, this optional extra creates a thermal barrier and additional gasket to offer even greater thermal efficiency.

Small but important uPVC mouldings that support the glazed units when installing them into a Liniar frame. We recommend only the appropriate Liniar glazing platforms are used with our products.

Designed to protect timber fencing panels from moisture seeping up from the ground. Liniar gravel boards can also be stacked to form a full fencing panel, if required.

Part of the Liniar balustrade system, and the only fully sculptured system in the UK, the handrail provides a beautiful finishing touch to any decking installation.

Usually refers to the handles, hinges and other non-uPVC elements of your doors, windows and conservatory.

The Liniar head vent clips to the top of the frame and allows the circulation of air to a property in a controlled and secure manner.

The metal locking points found on your doors or windows that are designed to accept the products locking mechanism.

Also referred to as the Outer Frame, this is the part of the window or door that adheres to the building, remains static and houses the opening sashes.

An optional extra on all Liniar doors, low thresholds provide family friendly and wheelchair access to properties. Some Liniar low thresholds offer thermally broken options for higher thermal efficiency.

The main outer frame housing a window or door.

The silicone seal between the outer frame and the wall, also used to seal all elements exposed to damp or moisture such as screw holes.

Steel or aluminium reinforcing combined with multi point high security locking system featured in our ModLok Patio Door and ModLok Bi-Fold

The vertical section that divides window units and provides structural support to the frame.

Refers to the inside of Liniar’s uPVC profiles or frames and helps to prevent the transfer of heat from the inside to the outside of the property.

Also referred to as the large or main frame, this is the part of the window or door that adheres to the building, remains static and houses the opening sashes.

Also known as the Sculptured style of window profile.

Part B refers to Approved Document B for Building Regulations, setting out guidelines for fire safety.

Part F refers to Approved Document F for Building Regulations, setting out ventilation guidelines and standards.

Part L refers to Approved Document L for Building Regulations, setting out thermal efficiency standards that all windows must comply with.

Part M refers to Approved Document M for Building Regulations and contains the guidelines set out for access to buildings.

Accreditation proving the enhanced security of Liniar’s windows and doors, PAS 24 has been independently assessed and guarantees your product is covered by a UKAS accredited certification.

The unit used to measure pressure, equal to one Newton per square metre.

The term passive house refers to standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling.

A licence for the sole right to exclude others from making, using or selling an invention, to protect the inventor from imitations. Liniar has a string of patents and Registered Designs across the whole range.

A set of doors with one or more glazed full sliding panels, often used to offer access to a garden. The Liniar patio door is available with 2, 3 and 4 pane options.

The vertical posts that provide support between bottom rails and handrails on the balustrade system, or vertical pickets as part of the Liniar fencing range.

Interlocking uPVC system used as an alternative to steel or timber piles. Has a variety of uses, primarily for the construction, environmental and flood prevention industries.

To provide a decorative finish to the top of Liniar’s twin-walled posts – can also be replaced with post cap lights for an alternate appearance.

For the Liniar fencing or balustrade system, posts are designed to perfectly match and provide sturdy structural support.

RAL numbers are the colour references used for matching colours on different types of products and surfaces.

The sash (the part of the window that opens) is sealed on the exterior side only and sits flush in a groove in the window frame.

The process of using all waste uPVC from the extrusion process to make alternate products – Liniar piling is made from 100% recycled materials and zero waste is sent to landfill.

Similar to a patent, however not as strict, a Registered Design relates to the overall appearance of the product resulting from one or more visual features.

Usually made from steel, reinforcement is essential in alternative uPVC window systems – the Liniar system is different in that it utilises less steel through its innovative design.

Made from uPVC, a Liniar residential door can be used as a front or back door for most properties and can be made in a wide range of styles and colours.

The framed part of the window that holds the glass in place, usually used to refer to the part of the window that opens.

A style of window profile, or frame, offering a sculptured edge which looks curved, rather than bevelled (chamfered). Often used for a more traditional appearance.

Products carrying Secured By Design status have been assessed and tested to meet the security standards of the Association of Chief Police Officers.

A moveable bar or rod that slides into a socket in order to securely fasten and lock a door.

Also known as cill, the external uPVC sill offers an attractive finish to a window and helps to prevent rainwater dripping directly onto the brickwork underneath. Internal sills are usually made from window board and can be painted to match internal décor.

Used in conjunction with fascias, soffits complete the transition between a building’s roof and wall, and to create an area able to accept guttering components.

Structural members that couple one window or door to another and increase strength to help installations with high wind loading or large apertures.

The starting point for a Liniar uPVC deck, the sub-frame is made from stainless steel and easily couples together to provide strength and stability.

The base uPVC profile, to which a laminated foil colour can be applied

Another patented innovation from Liniar, the thermal dam helps to prevent heat loss from the outer edge of the frame.

“Using less energy to provide the same level of service” is a general definition. In our industry that would be using less energy to keep your home at the desired comfortable heating level.

Offers a wide opening pane with the ability to let in fresh air whilst providing security. These window styles also offer great access for cleaning from the inside of the building.

Top caps hide a conservatory's framework for an attractive finish. Liniar top caps have a unique twin-wall design for added strength and enhanced thermal performance.

A strengthening crossbar, usually horizontal, that divides window panes.

An optional built in feature to allow ventilation, located at the top of the window frame.

Glazing units constructed from three panes of glass filled with either air or argon – considered more thermally efficient than double glazed units.

A measure of heat loss, expressed as W/m²K. The lower the U-value, the better the thermal efficiency of the product.

Unplasticised polyvinyl chloride, more usually called “PVC” or “uPVC” in the UK and Europe, or “vinyl” in the USA.

Uwindow is the window U-value for the standard size and configuration window as calculated according to EN ISO 10077 Parts1 and 2. The size and configurations of the standard windows used for rating is 1230mm wide x 1480mm high for domestic window installations.

A patented foam seal forming a watertight finish.

Window Energy Ratings – offering a clear way to show consumers the energy rating of a particular product. The familiar coloured ‘rainbow’ label is similar to those you will see on refrigerators and other electrical appliances, with A+ the most energy efficient.

The force applied to a structure as a result of the impact of wind.

Zero|90 is the name of Liniar's ground-breaking 90mm window and door system, which includes ultra energy efficient products including Passivhaus-certified uPVC casement and tilt & turn windows.