What is a triple glazed window?

To some it may seem obvious, but there is more to a triple glazing that just the three panes of glass within the sealed frame. Between each pane is a pocket of air or inert gas, such as argon; argon is heavier than air and works as an insulator for both noise and heat.

The third pane of glass located halfway between the inner and outer panes of double glazing creates two airlocks which improve the energy performance of regular double glazing by around 50%.

Energy efficiency is further improved by variables such as the type of air or gas used in the space between the panes, warm edge spacer bars around the perimeter to reduce thermal bridging and different coating on the glass to reduce energy loss from the inside. The frames themselves also have a large bearing on the overall performance (as well as the insulation).

We do not stop at three / Triple Glazing 

Some recommend that, if you already have new energy-efficient double glazing, then it isn’t worth switching to triple glazing, as you will only gain minimal improvements in energy efficiency.  It makes sense that single-glazed windows will undo any benefits gained from insulating the walls, roof, and floor of a house against cold spots, draughts, and condensation.  If you only have single glazing or double glazing with low energy efficiency, then triple glazing is a good investment.  Your home will be noticeably warmer, and you will save a considerable amount of money on energy bills.







Many times we get asked how do we deliver the superior performance that is expected from a triple-glazed system? To do that the window first needs to be engineered for three pieces of glass. Now, you may be wondering what in the world does that mean. In today’s blog post we will tell you just that.


  • The frame and sash need to be engineered to be able to hold the weight of three pieces of glass. Low-quality frames without adequate structural support will not be able to hold the weight of a triple insulated glass unit without causing short and long-term failures.


  • The hardware needs to be able to stand the additional weight of the triple glazed insulated glass unit. The stress of the extra weight will quickly take on low-quality hardware making it difficult to open, close, and lock the window or door.


  • The system needs to be engineered with high-quality components that work together to deliver superior performance for many decades.


  • The glazing cavity needs to be wide enough to accommodate three pieces of glass that are the right thickness without compromising the space between each pane of glass. Thin pieces of glass with small air gaps will not deliver better thermal and sound performance than a high-quality dual-pane system.


Many of our systems are Passive House Institute fitting components. They deliver the performance required to achieve Passive House Certification. Contact us to gain access to more information about our passive house certified products.