/ Home & Energy

Need new double glazing? Who would you trust to install it?

Only 7% of Which? members trust double glazing companies. Not that surprising when they’re renowned for dubious selling techniques, and steep price drops are a familiar part of the sales patter.

But building regulations mean we don’t really have a choice but to install double glazing when windows need replacing.

So when you’re shopping for new windows, should you trust the big names like Anglian and Everest, or should you go for a smaller, less well-known local firm?

Independent double glazers do better

Our latest satisfaction survey of double glazing companies found that that independent traders perform better and might even be cheaper.

The four big national companies (Anglian, Everest, Safestyle and Zenith Staybrite) are apparently leaving customers less satisfied than those who went with an independent double glazing company. As one Which? member said:

‘Local firms rely on word of mouth for their reputation and in a small town they cannot afford to let this slip.’

Local firms could be cheaper too

And, while you might assume you could get a better deal using a large firm, that’s not necessarily the case.

We sent a price questionnaire to Which? Local recommended double glazing traders to get the average prices you should expect to pay for different double glazing jobs.

We also sent the same questionnaire to Anglian, Everest, Safestyle and Zenith Staybrite. Both Everest and Safestyle declined to share their prices, with Everest telling us, ‘It’s no secret that we charge a premium price for our products’.

Anglian and Zenith both provided their prices, but we found that these were typically higher than those quoted by the independent traders who responded.

Problems getting double glazing

What’s more, those using local independents are also less likely to experience problems. Of those members who used local firms, around two thirds didn’t have a problem. But this figure fell to just over half for those who went with one of the big four companies.

The most common problems were: delivering the wrong parts, scratched glass, windows not fitting properly, installation taking longer than planned and installers causing damage to a property’s interior. Each of these problems were nearly always more common with the big four.

So, if you’re planning to get new double glazing, will our research influence whether you go for an independent or a big name? And if you’ve recently had windows fitted, who did you go with and how did they do?

Brenda says:
18 April 2012

I was amazed to read that Anglian was awarded three stars for its quotation process. This is a farce. Prior to the sales person’s visit, the manager rings to tell the customer about Anglian’s recycling scheme which is so successful that they are able to give a discount and gives the customer a code. When the sale person gives the initial high quotation and this is rejected, the recycling scheme comes into play and a “fantastic” reduction, eg 50% . Of course, the offer is only for TODAY, after which the recycling money is to be reallocated. We were honest and made it clear from the outset that we needed a week to get several quotations and make our decision. Notwithstanding this, the sales person would not accept this and we felt very pressurised.

We opted to purchase from a local company who were considerably cheaper than Anglian’s “fantastic” reduced price. The local company discussed our needs, measured up and went away to prepare their quotation which arrived a couple of days later. Ther was no pressure and the installation went well and we are very pleased.

In addition, the Anglian sales person who was described as a “window designer” wanted us to replace a window with a fully opening section with a window with just two fanlight sections. I was most concerned about this and rang FENSA who advised that this was illegal. I’m really glad we didn’t go with them.

pepperpotdot says:
23 April 2012

Could you please tell me which company you finally decided on and were you happy with their work. Thanks.

Gopal says:
8 November 2013

I can confirm that I have experienced this “today only” offer just yesterday and the price dropping by 50% drama as well.

fran hollick says:
22 January 2014

could you please say what company you decided to go with and how did you find there work? thank you

Lucian Marius Matei says:
14 May 2014

five weeks from survey no calls back on installation. I have called two weeks ago, no clue what’s going on, called one week ago again no clue, today I called (so please bear in mind that I called always) to find out that I need planning permission!!! Middle of the job, exchanging windows at no time at all, delays in a million pound project. Asked for cancellation, so the project will end up without windows renewed. They dont give a damn….SuperBad service at all. This company is shocking and have no other words but highest blood pressure ever. Shame on you Anglian

par ailleurs says:
18 April 2012

Nothing’s changed over the years. Reading the article made me feel good about using the same local firm for our previous 3 houses when windows needed replacing. You get a salesman who turns up on time, tells you what it will cost, takes a deposit and 3 weeks later the job’s done to a high standard by local workmen who know they have to be good or the customer will doorstep them till it is.
Do companies like Anglian (with whose salesman I had a particularly unpleasant encounter in the past) take us for complete idiots? Special, once only offers; sign up on the day or lose it; phone calls to the manager. No thanks! All I want is a good product, sensibly priced from someone who is not totally bonus driven.

pepperpotdot says:
23 April 2012

Please tell me which company you used. Obviously good or you wouldn’t have gone back 3 times. Thank you

Phil says:
19 April 2012

I wouldn’t touch Anglian with the proverbial but how did we get into the situation of having to buy replacement windows every few years? Once upon a time a house would have one set of windows which, with a bit of TLC, would last as long as the rest of the building. Now it seems we’ve been conned into believing that we have to have these dreadful plastic things that decay and fall apart in next to no time. I know people who are on their third set.

How do plastic windows decay, Phil?

Mine were put in about 20 years ago by a chap I know who had worked as a window fitter. He was able to give me useful advice on what features to look to and he knew where to buy the materials at a sensible price.

I have had no problems with moisture in the double glazed panels, except for one that was replaced due to breakage.

No more dripping, draughty windows. No painting, and easy to clean. Fantastic.

plastic windows do decay. as do aluminium and timber. Everything has a lifespan. Or have we fallen for the “maintenance free” slogan? Everything needs some form of cleaning, routine maintenance and care. Including windows. And watch what happens if you don’t.

Have to agree Wavechange

I had double glazing put in about 35 years ago – no sign of decay – as good as new. The added bonus was sound insulation something I never considered – but the sound pollution reduced to about a fifth of what it was before. Brilliant.

par ailleurs says:
19 April 2012

Plastic windows don’t decay as such but the fittings on cheaper ones can weather badly and that’s just as bad. Victorian sash windows often last almost forever but they are are seriously inefficient both thermally and for draughts. They’re also the Devil’s own job to paint properly. Of course they should be kept or replaced with like for like modern versions in sensitive areas but otherwise when they’re gone it’s usually for the best.
The windows I’ve replaced in the the last 30 years were either (a) only 15 years old wooden ones which were rotten due to poor quality materials (b) in my previous and current house 30 year old double glazing which was OK but nowhere near as efficient as the new fittings. My house is now warmer, more secure, less draughty and has no condensation problems.
By the way, I do open them regularly to ensure good ventilation which is something people forget about. You don’t want to be sealed in either!

Buying Double glazing was the only time I have used a cold caller – Still there 35 years later – Though I don’t think I’d do so again.

Colin Samson says:
7 August 2013

They said “. . using the same local firm for our previous 3 houses . . ) THAT is why they replaced their windows several times; they kept moving home & replaced the windows each time. It wasn’t because the windows didn’t last very long.

I have been in the replacement windows industry since 1981, so know a bit about the life of PVCu windows & doors. The products will easily last for 50 years IF they are decent quality to start with, installed correctly & are given the regular but minimal maintenance they require (mostly checking that drainage systems are free from blockage & that handles, hinges & locking systems are well lubricated a couple of times per year. Even so, some parts may require replacement occasionally, usually at minimal cost. Unfortunately, customers rarely do any maintenance at all (sometimes not even washing the frames for ten years or more) so in such cases of neglect, a realistic lifespan is closer to 15 – 20 years. However, most PVCu products are NOT replaced because they have reached the ends of their lives; they are replaced because more secure & better insulated products have become available, or simply because a property has changed hands & the new owner wants windows & doors of different designs & styles.

PVCu windows & doors now cost much less than half the price of made-to-measure timber products, so if they last longer than timber frames (without all the maintenance too) they are a much better buy too.

Phil says:
19 April 2012

Despite being stabilized uPVC still degrades when exposed to direct sunlight. There are other problems as discussed here:-


Phil says:
19 April 2012

Thanks Phil. So far there is no obvious deterioration in my uPVC in at least 20 years, possibly because I don’t have any south-facing windows. Good enough for me.

It’s about time that uPVC was properly recycled, but the same can be said of many plastics and other products.

I don’t think anyone would argue that wooden windows aren’t nicer to look at than many uPVC windows, however there is a huge cost difference – and again, there are good quality and poor quality wooden windows. With everything in life, you get what you pay for. As wavechanger has found – if the uPVC is of good quality then colour stabilisation is not an issue – both from the prevention of it turning orange or brown (as the really cheap uPVC did in the 70’s-90’s) and in the resistance to fading. The biggest issue in buying uPVC – and Everest were picked up on this on Watchdog the other week – is whether the uPVC used in the windows is from the same source as other components such as uPVC architrave and edging strips. Another reason to buy from a company that makes all it’s own uPVC to one formulation. I was surprised to see Everest picked up on that, as one would expect them to have better controls, but the contrast in the white shade of the window and edging strip was considerable and looked poor. uPVC windows have mechanical parts that need maintenance – cleaning, perhaps greasing or the application of a little WD40 – But the big advantage is no rubbing down, repainting, preserving etc. And security is better – if you fit good quality, that is.

I would argue that uPVC windows look nicer than wood, because so many wooden windows are left until they look rather tatty or worse. 🙂

I believe that uPVC is covered by one or more British Standard, so that could be the key to ensuring that quality is adequate for the job.

🙂 I think this thread is just proving that one gets what one pays for and one gets what one accepts! Some uPVC windows look far nicer than wood windows that are well maintained. The architraves and beading used on some uPVC windows are really very attractive whereas some wooden windows are very boxy and poor in design. You are right on the British Standards – manufacturers that meet or exceed them in anything that one buys for improving one’s home is the first consideration one should have,

Jim says:
19 April 2012

I used Everest to install windows in 2011. I was very disappointed in the final installation as workmanship was poor. I cannot see anything in the quality of the windows to justify their use of “the best”” windows arives with defects one of which was bad enough to be replaced. I would not recommend Everest.

Jeff Vincent says:
20 April 2012

Just how economic is double glazing? We now have several windows in which the double glazed panels have “blown”, that is to say, suffered from internal misting due I guess to both the age of the glazing (19 years) and possibly manufacturing faults, So if this is a common problem (which I believe it is) how can you confidently state that double glazing saves money if you have to replace it every 15 to 20 years?

I suspect this depends on the quality of the panels. I had the outer glass pane of a door panel broken, probably by the paper boy’s bike. The replacement panel failed in the way you describe, after about 3 years. All the original panels are fine and they are about 20 years old.

Like any other manufactured product 20 years ago (OK, 19) the technology used to make sealed units wasn’t so good as it is now – at least amongst the quality end of the market. The way sealed units are made has a big impact on useful life – ask the manufacturer if the units are made flat or upright (upright is good as the glass is not under stress while it bonds to the spacer bar, which takes 24-48 hours). And you don’t get distorted reflections when the panel is mounted in the frame either, with vertically made sealed units.

Also – 20 years ago the seals were of poorer durability – the amount of rubber one sees on windows of that era compared to good quality windows now is huge. The less rubber around the edge of the glass (not the seals in the frame to stop draughts) the more durable the sealed unit is likely to be – as well as more attractive.

Your original question is whether double glazing is economical, given the cost. Well, it depends, as ever upon the state of your existing windows and the amount of heat loss you have – given that a good set of windows will last 30-40 years, then over that period I’d say that you’d recover the cost several times over. There are estimates on independent government websites etc that suggest £600 a year upwards on reduced energy costs can be saved by replacing single glazed windows – though this estimate is going to depend upon the size of house, how well the house is insulated, how warm you have the heating usually, how many days of the year you have heating on, what type of heating you have (gas, electric, coal, oil…), how good your boiler and radiators are. But the savings are not just in heating costs – the pay-back has to include the lack of maintenance you need to do to wooden windows, the increased security that a good quality double glazed unit can provide, as well as the ‘feel good factor’ of having a home that looks in better condition than one that has peeling paintwork and ageing windows.

I bought replacement windows from a local firm (choosing from one of 3 such companies) with a supposedly good reputation some 12 years ago – after about 5 or 6 years the seals on them blew – these were large windows, with leaded lights and other features that cost a lot of money. Two of the top vents developed problems with the locking handles, too. I went back to the company and found they’d gone bust, so my guarantee was worthless. About a year later the guy who ran that company knocked on our door to tell us he’d started up another ( £100 limited liability) company selling windows and asked if we’d like a quote for replacing the windows we’d bought from him in his previous guise…! My wife suggested he honour the guarantee he’d given us in his last company – at which point he disappeared quite rapidly.

I replaced other windows with some from a national firm recently and am delighted with them – they look good, have meant I can turn off radiators in the bathroom, the fitting is excellent – the quality of the handles superb. And I am with a company that has been around for over 40 years and will, comparing their financial accounts with ANY of the local firms, be around to honour its guarantee – which, incidentally, is 15 years on the sealed units, a couple of local firms offered just five years.

Local firms? Sorry, won’t touch them with the proverbial. I don’t expect to replace my new windows for many decades. I know where my money is safest. And as to pricing – ANY direct sales company has dodgy sales people – the smaller the company, the more at risk you are. The big firms don’t risk their reputations by allowing their staff to create bad impressions and they weed out the sharks, mainly.

I bought fitted wardrobes recently – the sales person began at £13k and within 6 minutes and two phone calls to his boss was at £3.25k. The guy lost all credibility – it was only that my wife had made up her mind prior to the visit that the wardrobes were the only ones she liked that I went ahead… I called the company and described the process, the guy is no longer working for them.

If you are stupid – you’ll be caught out whatever you buy. Use some common sense. With windows you get what you pay for – look around any road on a sunny day to see horrible, cheap double glazed replacement windows – they look like cellophane is behind them and the reflections are distorted. These are cheaply made sealed units. The frames are also generally without character – plain and ugly. The real crooks are the people who sell such ugly windows and just try to get away with a low priced quick sale – they don’t have to look at the windows for years to come – either from inside or from the outside. Paying a premium for a well made, good looking product that one knows the origin of manufacture of – and which will be installed by the same nationwide firm and backed by the same company – not finger pointers who blame other third parties if things go wrong, is wise.

I seem to remember that the extensive criticism of double glazing companies related mainly to poor standards among big companies. All the problems my friends have experienced relate to larger companies.

Sometimes small companies will let you down, sometimes big companies will be the problem. The best approach is to get recommendations (or warnings) from others.

Colin Samson says:
23 April 2012

I have been a “double glazing” sales agent since 1981, so have a lot of knowledge and experience in the industry. The BIG problem is that the public is generally ill-equipped to compare and buy such technically complex products and services; they also are rarely prepared to spend the time, energy and sometimes the money required, to ensure they receive the high quality and value-for-money installations they quite rightly expect.

This problem is exacerbated by the fact that almost ALL the sales people are actually self-employed; they are paid NOTHING at all unless they make a sale! No wages, salaries, pensions or commissions, just an agency fee based on the pre-VAT price. Even that fee is at risk if they accidentally undercharge and the costs of running a car, telephones, computers & postal charges has to be paid from any fee received. Contrary to the common perception, few such sales people last long in the “job” as they rarely earn much money. We then end up with desperate sales people who are encouraged (by ALL the big companies) to lie through their teeth and offer ridiculous “discounts” for immediate sales. If the salesperson fails to get an immediate order, his/her “Sales Manager” will often cut out the sales person altogether by contacting the customer & reducing the price again. Even so, the end price can still be more than twice the price charged by a local company!

The high turnover of sales people also means that very few of them have much technical knowledge of windows & doors or of the various regulations governing safety glass, egress (fire escape requirements), ventilation and insulation. The result is that we have mainly unqualified sales people who are pressurised (mainly) by the larger companies to rush customers into deciding to buy products they have little knowledge of.

I have worked for double glazing companies of all sizes in the past 31 years. The larger the company, the worse the problems are for the customers, that is absolutely indisputable. The large companies have little reason to care about customer satisfaction; they just want to make as much money as they can. Instead of spending money putting right the problems (usually) caused by their sub-contract installers, they prefer to spend the same money on marketing.

People are usually unaware that big companies are often FRANCHISES. The company you buy from is not necessarily the big name company that pays for the TV adverts. Those companies are (understandably) reluctant to underwrite the guarantees of the company that previously held the franchise in their area.

My advice to potential buyers of windows & doors includes:

1. Research thoroughly before getting any quotations, especially impartial sources such as “Which?”.

2. Don’t take much notice of “advice” given by the various Trade Associations; they exist to help the companies, NOT the customers!

3. DON’T get “lots of quotes”, you will be unable to compare properly & end up with little more than a long list of prices.

4. Get two or three quotations from LOCAL companies. The best mix of price & peace of mind is usually found with those who have traded continuously for 10+ years. Be aware though, that the very cheapest prices are often given by “companies” that just consist of one or two installers who sell, survey, order & install everything themselves with no other staff to back them up; their only means of contact may be their mobile phone number. They often cannot afford to correct problems because they did not charge enough in the first place and you’ll be very lucky if you see them again.

5. Don’t compare PRICES. Compare value-for money and the features of the product. You MUST look at samples of the windows & doors being quoted for; they all vary in quality & design. Would YOU buy a car based just on the price quoted & the fact it has four wheels? Of course not!

The good news is that the “double glazing” industry and the products it installs, have come a long way since I sold my first windows in 1981 (yes, they are still in use!). There is no reason to be deterred from improving your home if you can afford to do so. Which?’s research shows that most customers are happy with their installations; tread carefully, take note of this “Which?” survey and you should be happy too.

Colin Samson FInstSMM

I don’t think anything meaningful can be drawn from the comparison. A small number of big firms will have a higher proportion of people complaining about them simply because of the considerably larger customer base and therefore skew the impressions, if not the actual results. Smaller firms won’t appear on these kinds of forums as people won’t think it’ll do any good complaining about them, as proportionately they each serve a tiny fraction of the market. I can make an educated assessment of product quality, strength, appearance, durability, likely lifespan on anything I buy – it just takes time to research, listen to various suppliers, question them, test the responses etc. I’ve not found any local companies who make their own UPVC, make their own sealed units, and design and make their own windows. As I found to my cost, trusting to a local company without a sound financial base, and who wasn’t responsible for the whole product from start to finish, proved to be a big mistake.
A far easier conclusion to reach is to look at the financial status of suppliers. A look at most double glazing companies on http://www.companycheck.co.uk tells anyone the likelihood of whether a company will be around to honour its guarantee. I would prefer to put my money in a bank than a china pig.

You are right that recommendations are useful – however with things like windows a recommendation 20-30 years after the windows were bought is what really counts – not just whether the guys who installed them were nice blokes who cleaned up after themselves a matter of weeks or months ago. So recommendations of less than a couple of decades – in the case of double glazing – is but a starting point in assessing suppliers. From that start point, go back to product quality, design, durability and strength, etc. And look at recent installations to see whether what is shown to one in the home is what actually gets installed. Local window companies who buy their windows from mass fabricators on the spot market cannot be trusted to always use the same suppliers – and therefore products can vary enormously.

Simon says:
2 October 2012

I tend to agree. Luxury cars also tend to have a poor reputation for quality because at that level people expect more.

My biggest gripe with the large companies is the whole quoting process. I was looking to have all windows and doors replaced a couple of years ago; I had visits from two national companies, both of whose salemen started off with ridiculous quotes which they immediately reduced by large amounts; both invited me to speak on the phone to “the boss” (which I declined); both offered inducements to sign immediately (which I also declined). One left me with nothing in print apart from his personal calling card, not even a brochure, and a verbal quote of around £9,000, down from the initial £20,000(!) The other, having started well into five figures (I can’t remember the exact amount), left me with a single sheet with a handwritten £7,600 which he would “see if he could get reduced a little more”, again no brochure. I subsequently had further phone calls, including ones after I had told them that I had the installation done by another company. I think the lowest price mentioned was just under £6K. Having rejected both of these companies, I invited two local companies for quotes. Both of these, having visited and measured up, left saying they would send a quotation in the post. I duly received quotes from both within 48 hours. Both quotes were fully itemised; one was for £4.5K, the other for £4.1K: no negotiations, no hassle, just a fair quote from the outset. I chose one of these companies to do the work, it was carried out and completed on schedule by experienced fitters, to, as far as I can tell, a high standard, with good quality materials. From my experience, I would advise anyone looking to have windows and/or doors replaced to consider local companies rather than the large national companies.

Les. Marshall says:
29 April 2012

I was a surveyor for 22 years with Everest. I have had Everest hardwood windows, entrance doors and a patio door installed at my bungalow for 20 years or so, without any problems, I apply a coat of micro porous varnish anually to the timber frames, other than keeping them clean I have no other maintenance to do.
Everest do charge a ‘premium’ for their products, but you only get what you pay for. I attended a number of attempted break-in’s of the Everest products, and apart from the ‘burglar’ breaking the glass to gain access, I only knew of one successful break-in, that was in the large area that I covered, the buglars had disconnected the house buglar alarm, the attending police officer discribed the burgulars as ‘professional’, the house owner purchased a new door from Everest.
Yes big and small companies get things wrong on occasions, and you cannot please all the people all of the time, that is life! But from my experience both working for Everest and having their products installed at my property, I would say that if anyone can prove to me that Everest products are not (or joint) best on the market, I would be interesting on hearing from them.
I am not ‘brain-washed’ with Everest, but seeing so many other manufactures products made with poor quaily materials and extreme poor security locks and fiittings, I am convinced the Everest products are worth every penny that they cost.

I have used Anglian windows they have almost completed installing windows and doors.
So far they have been back once to rectify problems ( including damage caused whilst installing ) they are due back to rectify again this week.
I was sold ( by the salesman ) windows that included safe and sound glass , this glass is supposed to eliminate noise to a much better degree than ordinary double glazing , and at 200 pounds extra per window you would expect that it would. The salesman assured me that it would meet my requirements by cutting out the noise of dogs barking and noisy neighbours. It does not work the only sounds it cuts out are background sounds. I feel at almost £8,000 Anglian Windows have mis sold me a product that just does not meet the mark . I have be advised that I need secondary double glazing to achieve the results I want !

Les. Marshall says:
3 May 2012

Hi Kavarna
Double glazed units will cut down on some sounds that you can hear from outside, but sound installation is a secondary frame installed with a gap between the the house windows and the secondary frame, a six inch gap is usually the best, in the cavity between the frames sound absorbant tiles are fit to the two vertical reveals and on the soffit at the top.
With a sound level meter, you can test the sound that your sealed unit windows cut out, example test, outside the window switch on a lawn mower or simular, inside record the decibels with the window open, then close the window and see what difference is shown on the meter.
Hope this helps.

If you look at the technical specs you’ll see that where such noise reducing windows are fitted there will be a reduction in decibel volume compared to standard glazing. But you won’t block out ALL noise and to think you will is frankly a little naive. But I’ve fitted similar products in places such as around the North Circular Road in NW London (one of the busiest and noisiest roads in the country – if not THE busiest and noisiest) and around Heathrow airport. The sound reducing versions (6.4mm + 4mm) do make a difference over and above the standard 4mm + 4mm panes – but you will need to do far more to barricade your home from allowing ambient and surprise noise to disturb you. Noise travels in through walls, windows, doors chimneys… It’s very difficult to compare whether you really need the upgraded panels until they are in. But I am sure of one thing, that if you removed what you have and put in the 4mm+4mm units that would be standard for most companies, you would notice what you’ve given up. The only cause for complaint that you have, would be if the salesperson told you they’d eliminate ALL noise. If they did he/she was stupid and you would be a bit naive in believing it possible, I am sorry to say. Secondary glazing remains an option for you – but I do wonder where you live that the outside noise is that bad? Even around the airport, fewer people put in secondary glazing, such is the improvement of double glazed sealed units even of standard 4+4mm panels, but especially those that use 6.4 + 4mm panes.

Recommendations from friends and neighbours aren’t necessarily the best reasons for choosing a double glazing firm. It seems the installation can vary from job to job and installer to installer even within the same company. There are some cowboys still at large; I know, I used one.
We were recommended to use a local company near to Harlow, Capital Windows (Essex) Ltd. Claiming not to employ salesmen the company forgot to mention that most of the staff were related so that the eldest brother was in fact the salesman. Avoid any company not accepting a credit card payment if you wish to pay that way; this company only took cash or cheques. It greatly diminishes your rights if you later encounter issues with rectification of problems if you pay by cash/cheque.
Companies subliminally, in my opinion, use FENSA as a sales feature but they (FENSA) only concern themselves with the method of installation and offer NO support to the consumer if you have other problems. FENSA claim to have their registered companies independently assessed but, seemingly, this does not cover the warranty period, post-installation, normally 10 years. The Glass & Glazing Federation (GGF) stated recently in an email that, in their opinion, properly made and fitted sealed units should certainly last longer than the usual warranty period of ten years and most probably 20 to 25 years. My only concern about this information is that FENSA and the GGF have exactly the same address in London!
Following the initial installation a crack developed in a frame. All in all, this took the company eight months to rectify and that was after countless phone calls, letters and, finally, a threat of court action. Incidentally, Which? Legal helped tremendously with this particular issue. As a final indictment of the company they fitted the wrong patterned glass in the bathroom – it was supposed to match that in the front door of the property – but by this time we just wanted them out of our house, such was our dissatisfaction with the whole episode.
Now, some five years on, I have two panes where the sealing has failed resulting in condensation forming on the inside of the units, and one handle inoperative meaning I cannot close a window properly. Since I have a 10-year warranty supported, I believed, by FENSA I contacted the company some time ago (by recorded delivery) but have had absolutely no acknowledgement or response from them. They are still trading. FENSA, meanwhile, have distanced themselves from any action against the company.
Sadly, it seems pure chance to have replacement windows fitted and not have some issues afterwards. How easily and quickly these issues are addressed is a measure of the company involved. A warranty is only of value if it is honoured; generally the consumer will only know this if there is a need to call upon it. Only then will you be able to judge the wisdom of your choice of installer.

Richard Manchee says:
14 May 2012

Dear Sir/Madam
I have just received a salutary lesson about the purchase of double glazing. It started in a fairly low key way with a telephone call from Zenith Staybrite asking me if I was interested in receiving a payment for trading in our elderly double glazed units for new ones. As the seals were beginning to shrink and the units were becoming draughty I thought that recycling the windows was a good idea. I was told the inspection process would only take a few minutes. The Zenith man duly arrived the following day and to our surprise my wife and I were subjected to a 3 hour sales pitch. However as we needed more effective double glazing units we listened to what he had to say. He gave us a quotation for 8 windows and a door (all B rated) of £12143, which after various incentives and acceptance of a finance package was reduced to his “Lifestyle” price of £9774. I referred him to an advertisement in our local paper in which a long established local company was offering the same package but with “A” rated units for £4366. The salesman then subjected us to a counterblast extolling the superiority of the Zenith product over all others especially those of local suppliers. We were also told that the fuel cost saving if we had A rated rather than B rated units would only save us 40 pence per year. I am ashamed to say that I caved in and accepted his quotation and signed umpteen times on the dotted line. Fortunately I then opened the May copy of Which and read the article on double glazing. My immediate reaction was to invoke the 7 day cancellation period and cancel my contract with Zenith. This prompted a rapid return from the Zenith salesman, presumably to persuade me to revert to change my mind. However after hearing my sales pitch, bolstered by the Which article he abandoned me as a lost cause. His parting shot was that he would have been prepared to reduce his price to £6900 if I had shown more determined resistance in accepting his previous “Lifestyle” figure of £9774.

I have since visited 3 local suppliers and the 3 quotes I have received so far are £3300, £3680 and £4366 all for A rated units with toughened glass where necessary. I am considering triple glazed units which cost a few hundred pounds more.

Fortunately I read the Which article in time to benefit from a potential saving of more than £6000 and be offered a superior product. The local suppliers gave me a simple and affordable quotation with the minimum of fuss. Why can’t Zenith follow their example?

Yours faithfully

Richard Manchee

Terry Clark says:
14 May 2012

I note that in Which May issue, you appear to just compare installations of new window frames with double glazing and nothing else.
We needed double glazing for our kitchen which has two windows 1750mm x 1000mm one of which faces north, however we did not want the trouble of having to re-decorate inside and re-plaster outside when the frames were changed.
A small local company replaced a panel in our patio door some years ago by simply inserting a new double glazed unit in the existing frame. I reasoned if they could do that with a patio door, could they do it with a window. A phone call to them revealed they could, provided there was sufficient rebate on the existing frame, it was sound, and was not metal.
Do the big companies tell you this? Of course not!
So we had the job done, consisting of three double glazed panels directly replacing the 3 single glazed panes in each window.
The total cost for the two windows was just over £600, far cheaper than if we’d had new complete units fitted.

Terry Clark says:
14 May 2012

I forgot to mention, the sealed units supplied were made to measure by Pilkingtons, my local supplier/fitter always uses this company for its double glazing.

Simon says:
2 October 2012

Most double-glazing companies use Pilkington glass, but cut to size within their own frames.

You (Terry Clark) are confusing window manufacturing companies with jobbing glaziers(nothing wrong with being a jobbing glazier – there is a place for all sorts of trades!). If you want a repair to a window, then go to a glazier. It’ll be cheaper than a new window in the same way as buying a new engine for a car is cheaper than buying a new car. Whether it’s long term worthwhile is another question. Window manufacturers can’t be held up to be somehow ‘bad’ because they concentrate on developing new products that are better, more efficient, more economical in the longer term, rather than be Mr Fixits.

Simon says:
2 October 2012

Our 19 year old double glazed windows were beginning to mist up – quite badly. Anglian Windows were fitting in our location. A 50% off leaflet came through the door. I ignored Which? advice and called them in for a quote, they came within a week. For 6 windows it seemed reasonable (especially with the latest security handles and hinges). For another £1000 we agreed to have another 4 obscure glazed units fitted. Then I haggled to round down further. I paid a deposit (by credit card). A surveyor came, took some cement crumbs away (may be an asbestos issue – but after checks, all was OK). Installed in 4 weeks, in one day 10:00 to 19:00. Some minor issues, so I did not pay the remainder. I inspected the next day. The installation manager came the next day, agreed all my (very minor) issues, corrected some on the spot. I saw some small scratches inside the glass on the upper hinged panel. He agreed to replace the unit. The installations were well-handled, the minor issues were at the manufacturing stage. All resolved amicably and very quickly. The improvement in sound-proofing was very noticeable. I think we can get back to no radiators on upstairs this winter. I personally was pleased with Anglian Windows.

Mark Pearce says:
27 October 2012

I have worked in the industry for many years (30) and today I own my own double glazing company KJM Group Ltd, we are based in Andover Hampshire. Most of the comments above are very true, national companies tend to send commission based reps to you and the sale is the difference between them being paid and earning nothing. They all will offer huge discounts for recycling and any other offer they can think of at the time, but sadly none of them are true. If anyone wants a rough guide for costs of an “A rated” uPVC windows then I would average, a houseful of windows at between £400-£450 per window, installed, including VAT. A bay window would not be one window I might add! This can only be used as a rough guide, if all your windows are 3000mm wide (10ft) then this would be way out. An average house window is 1200mm (4ft) wide, but some will be 600mm (2ft) and some 1800mm (6ft), this would be the make-up of a typical home in the UK.

Personally from my time in this industry, Ive heard horror story after horror story about the national companies and how they operate, the products are generally good, but the sales process and the price you can pay are way off the mark! Proceed with caution, never be pressured into a sale and remember you legally have a cooling of period after you have signed!

I recently needed to replace a 25 year old sliding patio door set. Wood or aluminium – not PVC. Avoided the large companies because of their commission structure and high prices. Through Google I found some relatively local companies, got prices, and found the manufacturer of the aluminium sections they all used to manufacture the windows. A phone call got very helpful information on both the door type and their view on the local suppliers. Visited the preferred supplier who showed us round his workshop and chose them on the spot. A good job resulted. But the other reason for a bit of research was the price differences – £1800 to £5000 for exactly the same job. For something you only do probably once that involves a substantial outlay you either gamble, or spend time investigating. Thank goodness for the internet!

Unfortunately, none of the national companies make the style of window I need for the front of my home – in a conservation area. Whilst the style is quite common in the area in which I live, it’s a very small part of the market nationally, so I am only able to go to local companies who will make them. I got three quotes, chose the most expensive for a variety of reasons, but one of them being the hope that by doing so I was investing in my home. Less than 5 years later I had blown seals and condensation between the panes. The company I used had gone out of business, the insurance backed guarantee turned out to be worthless. The investment was wasted. One of the other two local firms I had quotes from has also gone out of business, the other trades under a different name today, though they claim that’s all that’s changed. I am stumped because I MUST install windows in the same design; but I don’t trust any of the local firms not to cause me the same problems all over again. I am even considering getting single glazed wood windows made by a local carpenter – at least I’d be sure of the quality of wood and workmanship and have to accept the lack of thermal insulation. The market is full of small companies which are started up by former employees of the Nationals who think they can make a fast buck by undercutting their former employers by buying frames and sealed units from one of a limited number of manufacturers and put together in a local shed with no real quality controls to meet a low price expectation. Looking at Dun and Bradstreet reports for the majority of those companies makes frightening reading to anyone who thinks about who they are going to do business with – I’d recommend anyone thinking of paying a deposit to local window companies looks at how thinly capitalised the companies are so you don’t fall into the mistake I made. If you don’t have access to D&B then http://www.companycheck.co.uk is free to all and gives a few key metrics about all registered companies in the UK. Look at how much is in the company’s bank at the time of last account filing; the value of assets vs liabilities; and before even thinking about the quality of their products, decide if the information you see gives you confidence that they windows or doors will be an investment for you or a potentially costly error. There are good, small, local window companies out there – but to assume that they are all sound businesses, no matter how long they’ve been trading, and will provide products that are as well made as those companies who have substantial investment in factories and decades of track record, is as foolish as thinking that all the National companies are staffed by tricky dickies out to fleece you! But there are also good and not so good national companies, too. As with anything – caveat emptor. Do your research fully before even starting to look at products.

You can easily have the failed glazing units replaced, if that is the only problem.

I had wood window frames made-to-measure by Dempsey Dyer. I think they would point you toward a local installer to glaze and fit. If you need a full replacement they could be worth contacting.

There is no reason why your local carpenter should not provide rebates deep enough for double glazing. With wood frames you need to stand the glazing slightly above the bottom of the frame to keep the seal from sitting in water that may accumulate – and the bottom rail should allow moisture to drain away – otherwise eventually moisture will get into the glazing cavity. Also make sure the wood is properly treated to resist rot.

Thanks Malcolm – I don’t feel it worth putting in new sealed units into a frame that is probably of poor quality (in the end) too. If – or rather when – I do something it will be to replace the windows completely. My preference (if it were possible) is to go to a national company, with a guarantee that is worth something, where the components are all of a good quality and which I can see, touch and try first – with certainty that what I am looking at is exactly the same spec as would be installed in the house. I’ve been caught out by ‘the friendly local firms’ – who are not responsible 100% for their product performance and quality and change suppliers of frames and sealed units at will, it seems. Although I trust the carpenter to make a good product – I’ve seen some excellent things he’s made – I am nervous about the overall complexity of windows. They need to last 50 years in my mind and I don’t know that he will be able to provide the kind of specialist knowledge required in making windows that companies like Everest or Anglian will have. I’ll look at Dempsey-Dyer – but again, if the sealed units come from somewhere else, the frames from D-D and the installation is done by a third party, then I will be stuck for where to point the finger if things go wrong. In an ideal world, one or two of the quality nationals would make the style I need – I’d have greater confidence in the product and its guarantee and support.

notjohn20 says:
12 January 2013

I used Everest for 3 doors and then a local company for all the windows and a couple of patio doors. Everest are incredibly efficient in the run up to the sale and their selling style is probably just on the right of legality. Their bullying and high pressure (plus outrageous quotes) was the reason we went locally for the rest. Interestingly we have had a couple of problems 2 years down the line with both installations and the local company (Bergsons in Bucks) are out promptly and timely – Everest are a shambles and clearly not interested.
At one stage the call centre apologised for the attitude and pressure we got from the “sales manager” Dreadful company and I really feel sorry for more vulnerable peole who end up caught in their process.