A big question being asked by many people is “should I switch from double glazed to triple glazed windows?” and the main reason for asking this question ultimately comes down to the degree of energy efficiency people want to achieve from their homes. This is particularly true due to the continuing rising cost in energy bills from heating and cooling our homes.
When you start looking at energy efficiency and windows the main value you need to consider is going to be the overall U-value, our complete guide to replacement window ratings covers U-values and other relevant factors in much more detail. The U-value on new builds and on replacement window units will need to be less than 1.7 in order for them to pass standard building regulations. In the past the average U-value for a single glazed window would have been 5 and a double glazed window 3 or less, these improvements have been bought about due to a number of factors:
- The addition of low-emissivity glass which has an oxide coating to reduce solar radiation transmission.
- Gas fills in-between the panes of glass
- Double glass panes instead of single panes
- Wider cavity distances between two panes of glass
When you consider a standard U-value of less than 1.7 for building regulations you would think that was good, right? Well the average U-value currently required for walls in actually far, far less than that at 0.3.
So should you opt for triple glazing in your window replacements?
It’s hard to say for sure because the “real” benefits are questionable, let us explain.
Triple glazing is widely used in some parts of the world, in particular those with heavily cold climates, with U-value requirements of less than 0.9 on new construction and replacement windows. In order to achieve this many manufacturing changes have been made including the addition of krypton gas fills over argon and the insulation of window frames.
Now, a U-value that low may appear great upon first glance however the amount of energy and consequent money that you actually save is negligible and not worth mentioning. So from a financial point of view going from double glazing to triple glazing is certainly NOT worth the money if you intend to save on your energy bills. But, that’s not to say you shouldn’t switch.
Triple glazing begins to come into its own when you consider the comfort benefits it will give you. Consider this, if you live in a modern house or a house which has undergone many improvements to make it more energy-efficient then the likelihood is that your home is well insulated and protected against the cold, right? This means that if you have areas of your home; the floor, walls and ceiling for example, which have very low U-values (0.3 as an example) due to good quality insulation then window with a U-value at 1.6 will actually leave cold spots in your rooms. This can have the following effects:
- Condensation running down window panes
- Draughts from the window into the room
- Heat draw from the room
So by having triple glazed windows the overall result is that your comfort is significantly increased because you eliminate all of the above, particularly in well insulated homes.
Do Triple Glazed Windows Have Negatives?
Well, the short answer is yes! Any product is going to have negatives associated with it and triple glazed windows are no different. The two main negatives associated with triple glazing are:
- The overall cost in comparison to double glazing
- The heat absorption reduction associated with triple glazing
You can’t get away from the fact that the triple glazed replacement window prices are going to be around 50% higher than that of standard double glazing, and in some cases they will even be 100% higher. Now, considering that the triple glazed windows save you nothing on your home energy bills, is that a price worth paying?
Secondly, windows are capable of heat absorption and double glazing will reduce your heating requirements by absorbing and retaining heat, the same cannot be said for triple glazing however. Triple glazing will reduce the overall heat absorption characteristics a window offers and so it’s likely that you won’t reduce the amount you use your home heating system.
So are triple glazed windows worth the extra cost, the answer is yes and no, it really depends on why you want them. If you want triple glazing to save money then there’s probably little point in the short-term, however if you want them to improve your comfort and maximise your home energy efficiency then they’re probably the way to go.
If you want to get an idea of the cost differences between the two then the best thing for you to do is obtain a free quote for your home and ask the contractor what the likely cost difference will be.