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We know that triple glazed windows cost more to produce than double glazed, but how is that translated into the increase in triple glazed windows prices that the consumer pays? Let’s consider the commonest material used in the manufacture of double or triple glazing units, uPVC. The most popular variations of uPVC are plain white and a woodgrain pattern.
The following table shows typical prices for a consumer to buy a double or triple glazed window.
|Double glazing cost||Triple glazing cost|
|White uPVC||£330 to £390||£420 to £510|
|Woodgrain uPVC||£510 to £610||£610 to £690|
These figures do not include installation costs which can vary enormously between installation companies. Looking at the prices, however, shows the steep increase in cost between comparable double and triple glazing. Remember the actual cost will vary depending on variations in style, size, frame and so on.
So, what would be the cost of fitting out your property with triple glazing? Once again this will depend on many varying factors, but an approximate estimate will give you the following indicative prices to buy and install triple glazed units in your home.
If you decide to have triple glazed units installed in your home, remember that if you have more windows installed in one session, the cheaper each window will be. This is because a large proportion of the installation costs are to do with overheads, hire of scaffolding and other one-off payments. You can see therefore that it’s cheaper to have all windows changed at the same time rather than just one or two over a longer period.
How much will my heating bills reduce?
As we said earlier, if your existing windows are either single glazed or very old double glazed, then having triple glazed units installed will save you money on your heating bills. But how much will you save and is it worth replacing? The following figures might give you an indication of the kind of amounts we are talking about.
|Energy rating||Mid terraced house||Semi-detached house||Detached house|
|A++||£70 to £100||£80 to £130||£140 to £180|
|A+||£70 to £90||£80 to £120||£130 to £170|
|A||£60 to £90||£70 to £110||£120 to £160|
Energy efficiency is crucial in today’s world of higher heating costs. Even if you have insulated as much of your house as you can, you will still lose about 20% of the heat through old double glazed windows. Replacing single glazed and double glazed windows with the new technology triple glazed windows will save up to £200 per year on your heating costs.
How does triple glazing work?
Most people know that single glazing means windows with one pane of glass while double glazing means windows with two panes. Well, would you be surprised if I said that triple glazing means windows with three panes of glass? Each window has three panes with a gap in between filled with the inert gas krypton (this replaces the gas, argon in older windows). You know how much warmer double glazing makes your home well then you can imagine the extra insulation that triple glazing gives you. And it isn’t only thermal insulation either, triple glazing makes a good acoustic insulator, and provides better security too.
The parts of the world where triple glazing is most common are Northern European countries such as Norway and Sweden, but it is becoming more common in the UK as more and more householders realise the benefits achieved by using triple glazing rather than single or double.
Triple Glazing vs Double Glazing
To understand the difference between double and triple glazing and the benefits of triple glazing we need to start talking about the science behind them both. Don’t worry this won’t take very long.
You probably already know that we are encouraged to increase our energy efficiency and reduce our carbon footprint in our daily lives. Heat loss in the home is measured by something called the U-value. This is used to compare the heat loss in various parts of the house, such as walls, roof, windows etc. The U-value of single pane windows checks in at more than 5 while double glazed units used to score 3 but now score 1.6 (remember that smaller numbers are better in the U-value system). This is mainly due to the improvements in window technology and the increased demands of the UK Building Regulations. Double glazing has improved immensely by increasing the cavity widths between panes, changing the filler gas between panes and adding special coatings to the glass to prevent heat loss. This is all good of course but a U-value of 1.6 is nowhere near what the Building Regulations require for walls (less than 0.3). Windows are therefore the weak part in a building’s thermal envelope and need improvement to come into line otherwise cold spots and draughts will form around windows.
Countries such as Norway and Sweden already use triple glazing with a U-value of 0.8. To reach this value the filler gas has been changed from argon to krypton and the frame is insulated too. As always these innovations cost money and therefore increase the triple glazing prices that are then transferred to the customer.
Increases in thermal efficiency may be worthwhile in cold countries but many people argue whether the increased efficiency of triple glazing and their increased costs are really necessary for a climate such as found in the UK. Our government is still pressing for these improvements in glazing to be adopted throughout the construction industry and therefore built into British homes where its effect will be felt in terms of increased comfort.
That’s enough of the boring science stuff, what you want to know is how triple glazing will improve your life.
Triple glazing benefits
The benefits of triple glazing can be summarised in a few simple paragraphs.
- When compared to single or double glazing, triple glazing is noticeably warmer. Don’t forget that you cannot just have triple glazing on its own to feel the benefit, you must have excellent thermal efficiency in the walls, frames and roof as well.
- Reduces Condensation. It is a common problem with single and double glazed bedroom windows to wake up and find pools of water on the window sills. This is because warm air in the room cools on contact with cold glass and deposits its water vapour. You will almost never have that problem with triple glazing.
- Saves Money. If you have single glazed or really old double glazed windows then the increased cost of having triple glazing installed will save you money on your bills. If you already have modern double glazing, then it will be better to wait a few years.
- Improved Safety. The extra pane of glass will make it even more difficult for an intruder to break into your home. If you wish, panes can be reinforced for extra security too.
- Noise Reduction. All of us at some time have experienced the screams and shouts of children at play. This is a fact of life that we just have to put up with and most of the time it is a joy to hear. Sometimes though, all we want is a bit of peace and quiet to sleep, read or watch television. Triple glazing will give you that extra bit of quiet.
Are there any disadvantages?
So far all we have been talking about are the advantages of having triple glazed units installed. Believe it or not, there are disadvantages which must be considered if you are thinking about having your existing windows replaced.
- Compared to double glazing, triple glazed units are more expensive to buy. Because they are heavier they are more difficult to manhandle and therefore take longer to install leading to a higher installation cost.
- Return on Investment. The costs involved with triple glazing will take longer to be paid back than with double glazing. The savings on heating are relatively smaller between double and triple glazing than the comparison of expenditure between the two.
- Less light. More light is absorbed when travelling through three panes of glass than through two panes. Lack of light may be more noticeable if triple glazing is installed on north-facing walls.
- The extra pane and the stronger structure of the frame mean that there is a considerable increase in weight between double and triple glazed units. In fact, weight is increased by about 50%. The extra weight makes installation and transportation more difficult for the installer. Extra weight can also cause structural damage to the walls of your home. New –build homes will be designed accordingly with stronger structural members but upgrades from single or double glazed units will not have the extra support.
Is it worth having triple glazing installed?
If your existing glazing has been installed fairly recently and you have new double glazed units of energy rating A or A+, you will probably find that it is not cost effective to have your windows replaced. The benefits you receive from the extra pane of glass will not be worth the added expense. In cases such as this, it is much better to install secondary glazing as well as your existing double glazing or have thick curtains.
If your existing windows are single glazed or are some of the older model double glazing systems, you definitely will save a lot on your heating costs.
Don’t forget that increased thermal efficiency around the windows will only be worth having if you have also done everything possible to decrease the U-value of the walls and roof. Cavity wall insulation and additional roofing insulation to the standards required by the UK Building Regulations will be the best way to do this.
Who can I ask to do the installation?
When people talk about double and triple glazing, their thoughts automatically turn towards the big name installation companies that advertise on television and in the Sunday newspaper supplements. These companies, Anglian and Everest are very well known and have both been trading since the 1960s. There is no denying that all their products are excellent and are usually installed to the highest standards. In fact, for Anglian’s Triple PVCU product they supply a guarantee of 5 to 10 years, while Everest’s Triple Glazed Casement has a lifetime guarantee. Both these products have an energy rating of A++.
You don’t have to go to the big boys in the industry for your triple glazing needs. There are plenty of smaller local companies who, because their overheads are lower, are able to do better and cheaper deals. All that is required is for you to make sure they are a reputable company, who supply and install products complying with the Building Regulations. This means that the company must either be registered with FENSA or with the Glass and Glazing Federation (GGF). If you buy windows from companies who are affiliated with these organisations you can be sure that they are not a fly-by-night, unauthorised or cowboy installer.
There are many advantages and disadvantages to having triple glazed units installed in your home. Although no-one can deny that triple glazing will make your home warmer (as long as the walls and roof are insulated too), whether you choose to have them installed will depend on the type of windows you have at the moment. If your existing windows are single glazed, old fashioned double glazed or if your windows are rotten and need replacing anyway then it will be worthwhile installing triple glazing. If you already have modern double glazing, then it probably won’t be worthwhile replacing them at present. Wait a few years until they have deteriorated before deciding to upgrade.