Glazing

Efficient Double & Triple Glazing

Glazing

What is Double-Glazing?

All properties lose heat through their windows. Installing energy efficient double-glazing is an effective way of reducing your energy bills and keeping your home warmer and quieter. Double-glazed windows use two sheets of glass with a gap between them which creates an insulating barrier, whilst triple-glazed windows have three sheets of glass. Both options can deliver a high level of energy efficiency.

How Energy Efficient is Double-Glazing?

When choosing replacement double-glazed windows, you can check their energy efficiency by looking at the Energy Saving Trust Recommended logo and British Fenestration Rating Council (BFRC) energy label. The Energy Saving Trust endorses any windows rated B or above. The higher the energy rating, the more energy efficient it is.

Lower Costs

Replacing all single-glazed windows with energy efficient double-glazing could save you around £135 per year on your energy bills.

Less CO²

A smaller carbon footprint: by using less fuel, you’ll generate less of the carbon dioxide (CO2).

Glazing Efficiency

A-rated windows are the most efficient


Energy efficient double-glazed windows are available in a variety of frame materials (including uPVC and more traditional wood) and styles. These windows vary in their energy efficiency, depending on how well they stop heat from passing out through the window, how much sunlight travels through the glass and how little air can leak in or out around the window. Some double-glazing window and door manufacturers helpfully use a window energy rating scheme to show the energy efficiency of their product. This is similar to the one you may have seen on appliances such as your fridge, or washing machine. A-rated windows are the most efficient. To check a window’s energy efficiency before you buy, look at the energy label.

double glazing heat retention graphic

How many Layers of Glass do you need?

Double-glazing has two layers of glass with a gap of around 16mm between them. There’s also the option of triple-glazing, which has three layers of glass. Both A rated double and tripled-glazed windows are available.

What Type of Glass is best?

The most energy efficient glass for double-glazing is low emissivity (Low-E) glass. This often has an unnoticeable coating of metal oxide, normally on one of the internal panes – next to the gap. It lets sunlight and heat in but cuts the amount of heat that can get out again.

Double Glazing Benefits


  • Smaller energy bills: replacing all single-glazed windows with energy efficient double-glazing could save you around £135 per year on your energy bills.
  • A smaller carbon footprint: by using less fuel, you’ll generate less of the carbon dioxide (CO2) that leads to global warming.
  • Reduced condensation: energy efficient glazing reduces condensation build-up on the inside of windows.
  • A more comfortable home: energy efficient glazing reduces heat loss through windows and means fewer draughts and cold spots.
  • Peace and quiet: as well as keeping the heat in, energy efficient windows insulate your home against unwanted outside noise.
  • The costs and savings of double-glazing will be different for each home and each window, depending on the size, material. Savings will also vary depending on how much you currently pay for your heating fuel, these savings are based on a gas heated home.
triple glazing cutaway

Triple Glazing

Key differences compared to modern double glazing


If you are considering installing triple-glazed windows containing PLANITHERM glass, here are some of the key differences compared to modern double glazing.

money savings from triple glazing

Saving more on heating bills

Double glazed windows already have an optimised energy balance to maximise cost savings and exceed the requirements of current building regulations. Triple glazing allows a high level of solar heat gain, capturing warmth from natural daylight and drawing it into your home, combined with exceptional thermal insulation properties to keep the heat in. The outcome is a window that may well achieve and exceed the maximum "A+" window energy rating and provide an even lower U-value* for even more savings on your energy bills.

cozy warm living

Enhanced comfort & living

When it's cold we feel cold air flow near windows. We get colder in areas around windows and turn up the heating more than needed. The sense of warmth from room temperature and air flows is also influenced by the temperatures of the floor and wall surfaces and also of the windows. A larger temperature difference between the individual surfaces makes colder surfaces draw heat off the warmer surfaces. People feel their skin cooling, and this affects our sense of temperature. Triple glazing impacts on both the air flow and the surface temperature.

conservatory with triple glazing

Maximum comfort

As with modern double glazing, the enhanced thermal efficiency of triple glazed windows ensures that cold spots are eliminated. Triple glazed windows can also be optimised to deliver excellent thermal acoustic performance - minimising noise levels from outside. This can also be achieved with acoustic laminated glass or combining different thicknesses of glass in double glazing.

Enhanced security

By using laminated glass in double glazing, or by having an extra pane of glass in triple glazing, greater security can be provided keeping your home safe and secure.

Energy Efficient

Triple-glazing often = low U-values suited to low-energy and passive house projects.

Value for Money

Triple-glazing will return the value of your investment when fitted as part of correctly specified low-energy or passive house project.

Noise

Further upgrades to glazing material can achieve superior noise reduction compared to double glazing.

Double Glazing Benefits


  • Smaller carbon footprint.
  • More comfortable home: energy-efficient glazing reduces heat loss through windows and means fewer draughts.
  • Peace and quiet: as well as keeping the heat in, energy efficient-windows insulate your home against external noise.
  • Reduced condensation: energy-efficient glazing reduces condensation build-up on the inside of windows.
  • The costs and savings for energy-efficient glazing will be different for each home and each window, depending on its size, material you choose. Double glazing should last for 20 years or more.