Glass Types

Window Glass Types: How to Choose Glass for Windows

There are several different types of glass you can choose for your windows depending on needs, problems and conditions. By selecting the right type of glass for each room, you can optimise your house to be energy-efficient.

Window glass types

There are many different types of glass tailored to different needs in a home.

Glass technology has progressed dramatically over the last 30 years and every window and room in your home can be optimised for its unique conditions to ensure maximum comfort, security and energy efficiency:

You might think that glass is just glass. But, not all glass is the same.

Choose Your Window Glass for Each Room

When replacing windows, it's not just the style and colour of the frame to consider. Think about any problems you experience in each room of your house and we have a different glass that can help to improve this.

The right specialist glass for each room will optimise your home to make a significant difference to the comfort and enjoyment of your living spaces.

Window glass for each room

The Main Problems Solved by Different Types of Glass

  • Energy efficiency for cold rooms
    North-facing rooms don’t benefit from the natural light and warmth of solar gain. Trying to heat a room with no direct sunlight can be considerably more expensive as the heat gets sucked out of cold windows. U-values measure how much heat is transfered through a window to demonstate how energy efficient they are.

  • Protect furnishings from sun scorching
    If you have a south or south west facing room, curtains, carpets and furniture near the window become damaged by the harsh sunlight. Wood is especially susceptible to UV. Leather will fade and crack. Carpets become faded and curtains bleached. A glazing unit with an outer laminated pane of glass will block out up to 99% of harmful UV, helping to protect furnishings and fabrics. G-values measure how much heat is transmitted through glass from the sun’s rays.

  • Noise reduction for external noise intrusion
    Acoustic glass can't make a room silent but can make a difference – which is the closest you can get to soundproof windows. The specialist glass works by using two thicknesses of glass and has a sound dampening PVB layer sandwiched between one of the panes. This combined effect of different surfaces and thicknesses disrupts the energy of the soundwave and reduces noise transference. The laminated pane of glass also has the added benefit of reducing up to 99% of harmful UV, helping to protect furnishings and fabrics from fading.

  • Safety glass for vulnerable areas
    Glass is a superior material, but windows, doors and large expanses of glazing can be lethal to a person if they break upon impact from accidental collision. For this reason, to protect people there are strict regulations for the use of safety glass.

  • Laminated glass for extra security
    Laminated glass has an infused plastic laminate core that holds the glass together when broken, making it very difficult to gain access.

Window Glass Types Overview

Customer NeedOur RecommendationsHow It WorksWhen Suitable
Energy EfficiencyEnergy Saver Triple,
Energy Saver Plus Double 
Outer pane allows solar heat in and Low-E coating on inner pane reflects heat back insideIn elevations where overheating is not an issue e.g. rooms facing North and East
Lowest U-ValueUltimate Triple,
Ultimate Double 
Limits solar gain and insulates to keep the heat insideWhere insulation is required due to rooms overheating. Or where maximum heat retention is desired in a room.
UV Bleaching ProtectionEnergy Saver Security, Ultimate SecurityThe laminate provides UV protection for furnitureWhere wooden floors and furniture are susceptible to sun scorching e.g. rooms facing South and West
Noise ReductionNoise Reducing Double GlazingAcoustic laminate and air gap between the panes dampen sound wavesWhere external noise is an issue
SecurityEnergy Saver Security,
Ultimate Security
The tough laminate layer is very hard to breakWhen security is a concern e.g. Floor to ceiling windows and back doors
SafetyUltimate Triple,
Ultimate Security Triple,
Energy Saver Triple,
Energy Saver Security Triple
The pane of toughened glass breaks into small safe pieces if smashedTo meet building regulations

Choose the right window type for your home

We have 1000s of options to make your windows unique to your home.

Different Types of Window Glass

Low Emissivity (Low-E) Glass

Low-e glass is a type of energy efficient glass. It has a special microscopic coating that reduces heat transfer and reflects interior heat back into the room. The magnetron applied coating is a mixture of metals and oxides that fuse to the surface of the glass and it is this coating that helps to improve the energy efficiency of your home.

The coating is so thin it can't be seen by the eye and can be compared to the effect of placing a penny coin on the top of the Shard building in London.

Low-e glass is used in conjunction with Low-iron glass in our Energy Saver Plus double and triple glazing units, to create a very energy efficient window.

Low Iron Glass

Low-iron glass has a distinct clarity that can allow more UV light through the glass for increased solar gain. Solar panels use low-iron glass for superior harvesting.

Low-iron glass has a distinct clarity that can allow more UV light through the glass for increased solar gain. Ordinary glass has 475 parts per million (ppm) of iron content in the glass – which causes the blue/green hue of some types of glass. Low-iron glass has 70% less iron at only 150 ppm, making the glass visibly clearer to the eye.

Aquariums and museum displays use low-iron glass for superior visibility.

As mentioned above, Low iron glass is combined with Low-e glass in our Energy Saver Plus glazing units to create an energy-efficient window. The Low iron glass allows more UV light and heat energy into the room, while the Low-e glass acts as insulation keeping the heat energy in the room.

Toughened Glass

Glass is toughened by heating the pane to extreme temperatures of over 600˚C and then cooled rapidly. This results in a change to the break pattern of the glass.

When toughened glass is broken, it forms a pattern of small pieces that reduces any risk of injury – compared to standard glass with a break pattern of large shards. For this reason, it's used as safety glass.

Shattered glass patterns

Laminated Glass

Laminated glass has an internal PVB core that makes it much more difficult to break. It is used for safety in skylights to avoid falling glass and for superior security.


The laminated glass is created by sandwiching a layer of PVB (polyvinyl butyral) between two sheets of glass that are bonded together. The result is a super safe glass that doesn’t shatter in the same way that standard glass does. The glass is also much more difficult to smash open as a means to gain entry to a property.


Laminated glass also has the additional benefit of blocking up to 99% of harmful UV, protecting furnishing and fabrics from fading in direct sunlight.

Safety Glass

Safety glass is required by building regulations in glazed doors and windows at ground level (see below). But it can also be fitted to any windows or glazed doors you want to secure.

Safety glass areas

If you have small children or large pets, safety glass offers peace of mind. An internal glass door or sliding glass doors are a target for accidents for children or large dogs to run through. And the damage caused by large shards of standard glass is life-changing.

Building regulations stipulate that any glazing in the following areas must be safety toughened glass:

  • Doors up to 1500mm from the floor
  • Windows up to 800mm from the floor
  • Side panels to a door within 300mm to the sides of the door

Obscure glass

Obscure Glass

Obscure glass (sometimes called privacy glass) allows you to have more privacy in a room but without the need for blinds so you can retain the natural light.

Toilets, bathrooms, glazing in a front door facing a road or a bedroom overlooked by a neighbour can all benefit from privacy glass.

Technically, there are two types of obscure glass. Acid-etched has a frosted appearance which can be applied as a solid frost or in a pattern. Textured glass is formed in the production line when a piece of molten glass is pressed into a pattern mould. Once cooled, the glass retains a tactile pattern. Depending on the pattern, the glass can still have some level of visibility through it or can be fully obscured.

Acoustic Glass

Acoustic glass is specialist glass installed in noise reduction windows that can reduce the transference of sound and noise through the glazed window.

Acoustic glass mainly reduces noise by using different surfaces and thicknesses to disrupt the energy of the soundwave. Although it also works through a combination of:

  • The thickness of the glass
  • Asymmetric thicknesses of glass to disrupt the soundwaves
  • Argon gas between the panes
  • Depth of gap between the panes
  • Sound dampening laminate between panes

A window with specialist acoustic laminated glass can reduce noise by up to 40db.

Solar Control Glass

Solar control glass is designed to reduce solar gain. It has a specialist metallic coating applied to reflect away infrared radiation whilst allowing UV light through the glass. This results in a glass that can allow the maximum amount of light in balance with reducing the heat from the sun.

The main reason to use solar control glass is to avoid overheating and the need to use mechanical cooling with an aim for a more energy-efficient house. Solar control is also beneficial to create a more comfortable living environment.

Solar control glass is recommended where solar gain can be a problem in summer months for example windows facing south and southwest.

Mix Your Glass to Match Your Window Needs

Inside a glazing unit, panes of glass are separated with a spacer bar and wrapped with a bitumen seal that maintains an airtight unit. Under the spacer bar is a desiccant that absorbs any moisture to reduce humidity inside the unit. If you do have condensation on the inside panes, this indicates your seal has failed and the unit needs replacing.

A double-glazed unit has two panes of glass and four faces of glass. A triple-glazed unit has three panes of glass and six faces of glass.

Inside glazing units

Inside glazing units

In an individual unit, different panes of glass can be used. For example, Low-iron glass, toughened glass, laminated glass or obscure glass.

The panes of glass can also have coatings applied to specific glass faces. For example, Low-E coating.

By combining glass and coatings in a glazed unit, we can create specific windows to meet different needs for each room in a house.

Types of glass house direction

How to Choose the Right Glass for Your Windows

To optimise the windows for your home, the first stage would be to make a sketch of your house that plots where your windows are.

Use a compass so that you can map the direction rooms and windows are facing.

Then think about other factors that can have an impact:

  • Is there noise from a road or from neighbours?
  • Do you have a room that contains antiques or paintings you want to protect?
  • Have you had to replace a carpet or furniture due to fading?
  • Is security an issue for a secluded side of the house?
  • Do you have small children or pets that you want to protect?
  • Are there rooms in which you want extra privacy for?
  • Do you often have to close the curtains in a room to keep it cool?
  • Do you have a room that is a cold spot in the house that you avoid?
  • Would you like to decorate a window to make it stand out?

Once you have mapped out your windows and thought of any special requirements, you can plan the specialist windows required for each room.

By assessing your house and considering the different glass for each window, you can dramatically improve your home's energy efficiency and climate control. Cold rooms can reduce their energy bills by retaining more heat and rooms that overheat can be kept cooler, making all living spaces more efficient.

Significant savings can be made by reducing the fading and discolouration of furnishings and floors. And, the right glass can make your home more secure from intrusion and safe from accidents.

If you would like an expert to help you optimise your home, contact us to arrange an appointment without any obligation.

Commonly Asked Questions

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    Which glass is best for a window?

    Windows can be customised with a variety of glass types, each with their unique benefits. For those seeking crystal-clear views, low-iron glass is an excellent choice due to its exceptional clarity. If you want to keep your space cool and comfortable, Solar Control glass can reduce solar gain and prevent overheating. Low E glass is perfect for those who want to keep their energy bills low by reflecting more heat back into a room. Lastly, Obscure glass is a great option for those who value privacy.

  • +
    Are there unbreakable windows?

    The short answer is no. You cannot get unbreakable glass and windows. Even the thickest safety glass can crack. However, glass can be toughened or laminated so that it breaks in small pieces for safety or doesn’t shatter.

    Read more: Laminated safety glass...

  • +
    Why are windows still made of glass?

    The only real downside to glass is that it can break easily and shards of glass are a safety risk. In all other aspects, glass is a more superior material than plastic for use in windows and has not yet been improved. The first and most obvious is that glass has more clarity than plastic. Glass is a much harder material than plastic and is more resistant to scratches and damage. Glass is a very stiff material and does not flex and bend like plastic can. Glass has longevity and is not susceptible to UV damage like plastic.

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We Can Help You Choose the Right Glass for Your Home

Book your free quotation appointment with one of our local consultants who will discuss your requirements, show you samples and provide you with a free no-obligation quote.