Double Glazing Jargon Buster

Dorset Windows

Whether it’s a new door, new set of windows or brand new sky room, when talking double glazing knowing the jargon will help with communication and help to avoid any miscommunication.

Usually you will be asked a number of questions about what you are looking for, what you want and your preferences from there we will guide you to a number of solutions. To help with the process we have created the ultimate jargon buster with all the terms you need to know.


A – Z of useful terms and words


Argon Gas – A gas that is inserted to fill cavities within double-glazed units for improved heat retention.


Back Sealing – where the window or door is sealed and then a decorative trim is placed on top to hide the seal giving a better cosmetic finish and reducing the visual amount of sealant


Beads –  The strip that runs around the edge of the glass holding it in place in the frame.


British Standards (BSI) – A minimal standard of practises and products for UK based manufactures to adhere to.


Casement – A window that is attached to its frame by a pair of hinges tending to hinge outwards, occasionally inwards. Can be hinged at the top or side.


Façade – The front or face of a building.


Fensa – FENSA is a government-authorised scheme that monitors building regulation compliance for replacement windows and doors. Every FENSA Approved Installer, from large national brands to small local companies, is assessed regularly by us to ensure its standards are continually maintained.


Handing – Opening direction of the side hung window swing. A casement window or door may be left or right handed.


Integrity – The limits of a glass pane or window frame under which it can operate safely.


Laminated Glass – A type of safety glass that holds together when shattered consisting of two pieces of glass held together by an extremely tough PVB plastic interlayer.


Low Emissivity Coating (Low E) –.Windows with low emissivity coatings emit less thermal radiation than ordinary windows. In winter, these coatings can halve the rate at which a window loses heat compared to an uncoated glass window.


Multi-point Locking System – A lock with multiple locking points designed to offer improved security and performance for door and window systems.


Obscure Glass – Most commonly used in living areas requiring privacy, often used in bathrooms.


Safety (Toughened) Glass – Up to 5 times stronger than regular glass – reduces the occurrence of deadly cuts and bleeding in case of accidents by breaking into small, cube-like pieces. Also known as tempered.


Sash – The opening and moving part of a window or door.


Secured by Design – A police-led initiative to certify windows, doors, etc to meet a certain level of security.


Self-cleaning glass – Refers to a special coating applied to glass which makes it harder for water and dirt to stick to it.


Silicone Seal – Silicone sealant is a type of adhesive, most often used to create a watertight or airtight seal at the joint between two surfaces.


Spacer Bars – Used to separate the inner and the outer panes of glass to form a cavity width that offers thermal insulation.


Trims – Decorative colour coded mouldings made of PVC to give a neat finish


U-Value – The Thermal transmittance, is the rate of transfer of heat through a structure divided by the difference in temperature across that structure. The better-insulated a structure is, the lower the Uvalue will be.


Window Profile – Also referred to as the PVC or Aluminium system, determines what the finished window looks like (product design). Profile 22 Optima, Deceuninck, Eurocell, Smart are some examples.


Window Energy Rating (WER) by the British Fenestration Rating Council (BFRC).  BFRC rated windows are independently verified by experts for their ability to Reduce your energy bills; Cut your carbon emissions; Improve comfort in your home.  The BFRC ‘rainbow’ label is proof your windows and doors will perform as promised. Accept nothing less.



Trusted & Recommended, with over 25 years of Experience


At Dorset Windows Ltd we pride ourselves on our approach we take to the business of PVC and Aluminium Home Improvements. As a family owned and run business; we all work to ensure that we exceed customer expectation and deliver quality and service that is second to none but at sensible prices.


You can rest assured from initial conversation until the completed installation the same professional, friendly, courteous and experienced attitude will prevail. We are happy to provide a free, no obligation quotation and will work to find a time that is good for you to meet with our experienced sales co-ordinator. Give us a call on 01202 825225 to find out what solutions we can offer you.

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