Energy efficiency is crucial in today’s world of higher heating costs. Even if you insulate as much of your house as you can, you still lose about 20% of the heat through old double glazed windows. Replacing single and double glazing windows with new technology triple glazed windows will save up to £200 per year on your heating costs.
For a typical 3 bedroom terraced house in the UK, the cost of triple glazing will be about £2,500. Thus, making the cost per window between £450 and £700 depending on the style. Of course, the outlay will also vary depending whereabouts you live. In London and the southeast of England, the prices will be significantly higher. For example prices in Surry can be 3 or 4 times as much as in rural Wales.
Cost of Triple Glazing
We know that triple-paned windows cost more to produce than other insulated windows, but how do we translate that into the increase in price that the consumer pays? Let’s consider the commonest materials used in the manufacture of triple glazed windows, plain white and woodgrain patterned uPVC.
First, a comparison of typical retail prices for a triple glass window in both style frames.
| Window Style | Retail cost |
| White uPVC | £420 to £510 |
| Woodgrain uPVC | £610 to £690 |
These figures don’t include installation costs, which can vary enormously between installation companies. Looking at the prices, however, shows the steep variation between both frame types. Remember, the actual cost will vary depending on variations in style, size, frame and so on.
So, what would be the cost to fit out your property with triple insulated glass? Once again, this will depend on various factors. But, the following approximate estimates show how much it could cost.
| Property Type | Bedrooms | Windows | Indicative cost |
| Flat | 2 | 4 | £2,000 |
| Terrace house | 2 | 5 | £2,500 |
| Semi-detached house | 2 | 7 | £3,500 |
| Semi-detached house | 3 | 9 | £4,500 |
| Detached house | 3 | 12 | £6,000 |
| Detached house | 4 | 15 | £7,500 |
If you decide to have these windows installed in your home, remember that the more you buy, the cheaper they’ll be. This is because a large proportion of the installation costs cover overheads, hire of scaffolding and other one-off payments. Therefore, you can see it’s cheaper to change all windows at the same time rather than spread them out over a longer period
Benefits of Triple Glazing
Let’s summarise the benefits of having triple glass windows.
- Warmer. When compared to other types of glazing, triple glass makes your homenoticeably warmer. Don’t forget, you must also have excellent thermal efficiency in the window frames, doors, loft, and walls to feel the benefit. So get insulating.
- Reduces Condensation. You’ll often find pools of water on the window sills with other forms of glazed bedroom windows. This is because warm air in the room cools on contact with cold glass and deposits its water vapour. You’ll rarely have that problem with triple glazing.
- Saves Money. Changing from your old windows to triple glazing will save money on your energy bills. However, If you already have modern double glazing, then it’ll be better to wait a few years until glazing technology improves.
- Improved Safety. The extra pane of glass will act as an additional barrier against anintruder. If you wish, you can have reinforced panes for extra security too.
- Noise Reduction. All of us at some time experience the squeals and shouts of children at play. Most of the time, it’s a joy to hear this. Sometimes though, all we want is a bit of peace to sleep, read or watch television. Triple glazing will provide that extra bit of quiet.
Triple Glazing vs Double Glazing
To understand the benefits, we need to consider the science behind double and triple glazing. Don’t worry this won’t take very long.
You probably know that the government encourages us to increase our domestic energy efficiency. We measure heat-loss in the home by something called the U-value. Thiscompares the heat loss in various parts of the house, such as walls, roof, windows etc.
Remember, smaller U-value numbers are better than larger ones! Single–pane windows check in with a U value of more than 5 while double glazing used to score 3 but now score 1.6. This is mainly due to the improvements in window technology and changes in the UK Building Regulations. Over time, better technology increased the cavity widths between panes, changed the filler gas and added special coatings to the glass to prevent heat loss. Although good, U-value of 1.6 for windows doesn’t compare with 0.3 that the Building Regulations require for walls. Therefore, windows are the weak part in a building’s thermal envelope and need improvement otherwise cold spots and draughts will form around windows.
Countries such as Norway and Sweden already use energy efficient glazing with a U-value of 0.8. To reach this value they have changed the filler gas from argon to krypton and insulatedthe frame. As always, innovations cost money which passes on to the customer.
Increased thermal efficiency may be worthwhile in cold countries. But, many people argue whether we need increased efficiency (and costs) of triple glazing in the British climate.However, our government still presses for the construction industry to adopt glazing improvements and build them into British homes. We’ll then feel the effects in practicalterms of increased comfort.
Right, that’s enough of the boring science stuff. You want to know how triple–glazing improves your life.
Glazed Window Styles
Despite energy efficient glazing being a recent innovation, manufacturers haven’t been slow to apply the technology to modern frames. In practice, you can buy triple glazed frames in the same styles as for older glazing methods. Let’s look at three of the most popular styles.
- Casement windows. Commonest and simplest style. Hinged on the sides like traditional designs.
- Bay windows. Create spaciousness, give panoramic views and allow more sunlight to enter.
- Tilt and turn windows. These open inwards to allow easy cleaning. The sashes tilt to provide secure and stylish ventilation.
In each style, you have a choice of uPVC, wood or aluminium, each with their own benefits. uPVC comes in white or woodgrain finish and is virtually maintenance–free. Aluminium is strong and durable and doesn’t need much maintenance. Whereas wood frames look good in period homes, they’re now made with laminated wood preventing warp and twist.
Finding Installers
When people consider energy–efficient glazing, their thoughts automatically turn towards the big–name triple glazing suppliers. These companies, such as Anglian and Everest, advertise on television and in the Sunday newspaper supplements. They’re very well known and most of this crowd have been trading since the 1960s. You can’t deny that all their products are excellent and they install them 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++.
However, you don’t have to go to the big boys in the industry for your triple–pane windows. There are plenty of smaller local companies who have lower overheads and offer better and cheaper deals. All you need to do is find a reputable company, which supplies and installsproducts complying with the Building Regulations. This means the company must either be registered with FENSA or with the Glass and Glazing Federation (GGF). Furthermore, if you buy windows from companies who affiliate with these organisations you can be sure they’re not a fly-by-night, unauthorised or cowboy installer.
Household energy–saving benefits
As we said earlier, if you have old style glazed windows, then installing triple–glazed unitssaves money on your heating bills. But how much will you save and is it worth replacing? Calculating the costs and savings might give you an indication of how much we’re 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 |
Are there any disadvantages?
So far all we’ve talked about are the advantages of having triple glazed units installed. Believe it or not, there are disadvantages which you must consider if you’re thinking about having existing windows replaced.
- Costs. Compared to older style windows, triple glazed units are more expensive to buy. They’re also heavier and more difficult to manhandle, so take longer to install. The installation costs are therefore higher.
- Return on Investment. The costs involved with triple glazing pay back over a longer time. In fact, the savings on heating between double and triple glazing is far less than the comparison of expenditure between the two.
- Less light. Three panes of glass absorb more light than two panes. Usually, this is okay. But, less light may be more noticeable if you install triple glazing on north-facing walls.
- Heavier. The extra pane and the stronger frame structure gives a considerable weight increase between double and triple glazed units. In fact, weight increases by about 50%. This makes installation and transportation more difficult for the installer. And, extra weight can cause structural damage to the walls of your home. New –build homes have stronger structural members built-in, but upgrades from single or double glazed units won’t have the extra support.
Glazing and regulations
You don’t usually have to apply for planning permission if the new windows have a similarappearance to the existing ones. However, if you live in a listed building or a conservation area, you might have special restrictions that you need to follow. Contact the planning office to find out.
All replacement glazing must comply with the Building Regulations for thermal efficiency, safety, ventilation, fire safety and means of escape. The Planning Portal discusses all these at great length but you should have a basic knowledge of them. To comply with the regulations you can use a company registered with the relevant competent person scheme. This bypasses the Building Control office and allows the company to issue a compliance certificate. Alternatively, you can use an unregistered installer and have the Building Contol inspector approve the work.
If the installer gives the customer a FENSA certificate. It assures the customer that the installer fitted the windows (or doors) following the Building Regulations and they registered the work with the Building Control Office. You need a FENSA certificate when you come to sell your property.
Triple Glazing Cost FAQs
What is triple glazing?
Most people know that single glazing refers to windows with one pane of glass while double glazing means windows with two. Well, would it surprise you if I said that triple glazing has three? Each window has three panes with a gap in between filled with inert krypton gas (this replaces argon gas in older windows). You can probably imagine how much warmer triple glazing makes your home compared to double glazing. And, you don’t only get improved thermal insulation either. Triple glazing makes a good acoustic insulator and provides better security too.
Northern European countries such as Norway and Sweden commonly use triple glazing. But,it’s becoming more common in the UK as more and more householders realise the benefits.
Should I have Triple Glazing Installed?
If you had existing glazing installed recently, you probably have new double glazed units of energy rating A or A+. If so, you probably won’t find many cost benefits if you change to triple glazing. The benefits you receive from the extra pane of glass won’t be worth the added expense. In cases such as this, it’s much better to install secondary glazing as well as your existing double glazing. However, if you have existing single glazed windows or some of the older model double glazing systems, you definitely will save a lot on your heating bill.
Don’t forget, it’s only worth having improved thermal efficiency around the windows if you’ve already done everything possible to reduce the U-value of the walls and roof. The best way to do this is to upgrade cavity wall insulation and roof insulation to the UK Building Regulations standards.
What are the disadvantages of triple glazing?
If you already have modern double glazing, you’ll spend out far more in installation and purchase costs than you will save on your heating bills.
Triple glazing won’t save you much more energy than good double glazing.
Extra layers of glass will decrease the amount of light let into your house.
Triple glazed opening windows are heavier than double glazed.
Does triple glazing reduce noise?
Yes, the sound travels through three layers of glass and two layers of ‘filler’ gas. This might not sound a lot but, it’s very noticeable if you have a noisy road outside your window. You can further soundproof the glass by installing a special plastic coating onto the panes.
Is acoustic glass better than triple glazing?
Yes. Manufacturers design triple glazing to have thermal efficiency. Unfortunately, sound deadening properties are only a useful side effect. Acoustic glass, on the other hand,absorbs, reflects and dampens sound waves far more.
How long does triple glazing last?
If they’re maintained they will keep their appearance indefinitely. However, the energy efficiency depends on how long they can keep the ‘filling’ gas trapped between the glass panes. Most manufacturers reckon that the gas seal lasts about 20 years.
Why do triple glazed windows mist up?
As long as the misting occurs on the outer surface of the glass pane, it’s perfectly natural. Usually, this happens first thing in the morning when warm moist air contacts the coolerglass. The warm air subsequently cools and its moisture condenses onto the glass surface. However, if you have mist between the glass panes, you have a damaged and leaking sealed unit. If you still have a guarantee on the window, contact the installer or manufacturer.
Get Quotes From Triple Glazing Suppliers
Usually, triple glazed windows will make your home warmer than it was before. Taking into account the age of your existing windows will help you decide whether it’s cost–effective to install them.
You can contact a window installer yourself but make sure they have all the necessary training and registrations. Otherwise, use the form on this page and you can use the installers we’ve already found and vetted. They will send you 3 or 4 estimates for your proposed work.
