Windows come in all shapes and sizes but buying them doesn’t have to be a confusing experience. Here at Raven, we’ll explain your options in simple terms and recommend the best products for your budget and what you want to achieve.

New windows guide

A quick research of the windows market will tell you there are hundreds of types and specifications.

Choosing your windows can be as simple as sizing them up and letting an experienced contractor present your options, but for those of you who want to know a bit more, you’ll find the information below most helpful.

Types of glazing

Windows are available with single glazing, double glazing or triple glazing.

Double glazing

Out of all these, double glazing is the most common in the United Kingdom. It’s around three times as efficient as single glazing and three times cheaper than triple glazing, making it a good middle ground for most homes.

Single glazing

The only time you would opt for single glazing is if you are in a listed building, and the local authority won’t let you upgrade to new double glazing. In this instance, they will likely insist on single glazing to maintain the period character of your house.

Triple glazing

Triple glazing is the best option for maximum efficiency and noise insulation. In Canada and Scandinavia (where the temperatures drop much lower than here) triple glazing is standard-fit. If you have an eco-house, triple glazing will probably be best.

Types of window

Imaged above: Triple glazing being made.

Types of window

The type of window you choose is likely to depend on what your existing windows are, or what windows other properties in your area have.

Here are the commonest types of window in the UK:

  • Casement windows
  • Sash windows
  • Tilt and turn windows
  • Fixed windows
  • Bow and bay windows


The most common type of window is the casement window with a side hinge. This is the standard window you find on houses in the UK. Casement windows can also open on a hinge from the side or bottom to suit the setting.

Sash windows

Sash windows are popular because they are beautiful. They usually utilise two sashes which operate independently, sliding up and down with weights so they don’t tumble. Some models have a single moving sash (usually the bottom one).

Tilt and turn windows

Tilt and turn windows have a dynamic hinge which allows the window to open out at virtually any angle. This is beneficial because it allows you to maximise airflow into your home depending on which way the wind is blowing.

Fixed windows

Fixed windows don’t have a hinge and are useful in applications where there is no desire for the window to open, such as on the ground floor. You’ll often find fixed windows installed alongside secondary glazing in older homes.

Bow and bay windows

These windows are large and composed of several panes. Pound-for-pound they are the most expensive type of window because of their scale. It is common for these windows to be fixed up to near the top where there will be an openable pane for airflow.

Sash windows

Imaged above: New sash windows made from hardwood. 

Types of window material

Windows are commonly made from timber, aluminium or UPVC.


Timber is the romantic choice. It’s organic, extremely durable and has a unique character other materials can’t match. It’s also a sustainable choice, since timber is easily recyclable and grown specifically for this industry. Softwoods and hardwoods are used – softwoods are cheaper but not as durable as hardwoods.


UPVC is the most common material used to manufacture windows. In fact, it’s one of the most manufactured plastics on the planet. It can directly replace timber and is the preferred choice because it’s cheaper and doesn’t need working. You lose some of the character of timber, but UPVC is much lower maintenance.


Aluminium is the most expensive option but the preferred one in modern premium builds. It’s stronger than UPVC and timber so the frames can be a lot thinner, which is why you see so many bi-fold doors made from aluminium. Aluminium windows look good with a brushed finish and will last longer than timber and UPVC.

Timber windows being made

Imaged above: A timber window frame being constructed. 

Windows and energy efficiency

In light of it being impossible for homeowners and installers to test the energy efficiency of windows, there’s a common standard which manufacturers use to disclose the energy efficiency of their windows. This is called the U-factor or U-value, which is determined by the manufacturer during factory tests.

Here’s a simple explanation of U-values: The U-factor and U-value is the overall heat transfer coefficient of a window. Simply put, it represents how much heat is lost through a window. A lower U-value is always better.

This is the only thing you need to know: a lower U-value is always better. So long as you stick to this rule of thumb when choosing your new windows, you can’t go wrong. But what is a good U-value? What should you look for?

With double glazing, a good U-value would be between 2.0 and 2.8. With triple glazing, a good U-value would be anything below 1.5.

Window energy ratings

To make choosing energy efficient windows even easier, there’s also an energy efficiency rating sticker system for windows. Somewhat confusingly, however, there are several rating schemes which have different stickers.

Here are the main ones:

Window energy ratings

The schemes in question are the British Fenestration Rating Council (above left), the British Standards Institute (above centre) and CERTASS (above right).

As you would suspect, A-rated windows and above are highly efficient. However, some B-rated windows are absolutely fine. At the end of the day, you pay more for a more efficient window but anything from B upwards is a good window.

Energy efficiency and windows

Imaged above: A double glazed window with normal condensation. 

New window costs

If you’ve made it this far, you might already know what we’re going to say — and that is the cost of your new windows depends on the type of window you choose, the glazing, the U-value, the material and also the quantity of units.

You can pay anywhere from £300 to £2,500 for a single double-glazed window, and custom-made windows run anywhere from £2,000 to £5,000.

To give you a ballpark figure, five A-rated double glazed UPVC windows will set you back between £2,200 and £2,800. You can add £1,000 to this price if you choose sash windows over a generic casement window or fixed window.

If you budget £500 to £600 per UPVC window, you’ll be about there. For timber, add £50 to £60 per window, and for aluminium, add £150 per window.

Double glazing

Imaged above: High-end sash windows and upper fixed windows. 

Fancy some free advice?

At Raven Bespoke Improvements we are experts in all aspects of windows and we genuinely want to help you choose the right windows for your home.

We provide free advice and free home surveys, during which we will recommend the best products for your budget and what you want to achieve.

We have over 30 years’ experience and we’re a 5-star reviewed contractor with Rated People and My Builder.

We’re based in Carshalton and serve the south of England, but we’re happy to drive for larger projects. Email us at or call us on 0800 009 6065 / 07984 293 894 for a friendly chat. Advice is free.


The Team,

Raven Bespoke Improvements.

Raven Bespoke Improvements
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Martina Cunningham
Martina Cunningham
10:53 19 Jun 20
David replaced several large misted units for us. He was helpful, professional... and excellent value. Will use him in future and readily recommend more
Ana Reed
Ana Reed
20:27 15 Jun 20
Great customer service, very helpful advice and lots of support - thank you... very much!read more
Pamela Swann
Pamela Swann
12:59 08 Jan 20
David has just completed a project for us and was superb. Would highly... recommend, everything was easy, from initial contact to completion and a fantastic finished result. Absolute pleasure to deal with. Thank youread more
james craig
james craig
10:59 20 Dec 19
David fitted new windows and French doors for us. He is without doubt the best... tradesman we’ve ever used and we would highly recommend him to anyone. Punctual, professional, efficient and takes pride in his work. We were happy to leave David and his excellent team working in our house when we were out. Everything was left spotlessly clean and the work was done to a very highly standard very quickly. David fixed a broken gutter for no extra charge and readjusted a door, neither of which was part of the agreed job. Thanks a lot David for a flawless five-star service just before Christmas!read more
Mark Hammond-Edis
Mark Hammond-Edis
20:55 19 Dec 19
David and his team helped us take a window out to fit a large sofa in our front... room. He was very responsive, polite and punctual. The job they did was difficult and they did it to a high standard making sure everything was perfect before they more
Edward Hordley
Edward Hordley
21:30 11 Dec 19
Hired David and his team on a repair and finishing job after having been let... down by another contractor. His approach was superb, professional, polite and very responsive. His price is higher than some, but he is well worth the extra investment. The value for money you get from him and his experience is exceptional and I have no regrets about using him or the work provided. This was not a straight forward job but David made it feel that way. Highly more
Paula Charman
Paula Charman
15:27 02 Oct 19
Thank you for a great job on our windows and doors. David was very professional... and very clean while working. I would highly recommend his services to other people. Thanks David Paula and Richardread more
Raj Thakker
Raj Thakker
16:03 24 Sep 19
One word: Superb. Thank you David for a brilliant job on replacing my... conservatory roof. No task was too big or small. David even took it upon himself to fix a broken gutter at no extra charge. The whole job was done at a very good price. Very clear communication, tidy and very professional at all time. I already have recommended him to my brother-in law and will continue to do so to others. Thank you David!read more
15:37 20 Sep 19
David provided an excellent service recently on a job. The quality of his work... is outstanding and I would fully recommend him. I have asked David to come back to quote on another job. He has just done that for me and I look forward to the works being carried out as I know the result of his work will be more than more
Anneke Meiring
Anneke Meiring
08:15 20 Jul 19
David is the best and most reliable contractor I have ever met. He converted... our courtyard into a conservatory. This was done at a very high standard. It looks amazing and is completely waterproof. He came across a lot of unforeseen problems in the process, e.g. had to clear a drain, move an extractor fan, level the ground area etc- which he attended to effortlessly as part of the job.He also assisted us with many ancillary and unrelated matters, e.g. putting my clock up against the wall, remove old window frames, liaising with another contractor on damp issues elsewhere in the house- all without charging extra as other contractors would do.He is super professional in the execution of his work and regularly updated us as to where we are in the process. He also has wonderful bedside manners, a superb sense of humour, and a humane touch. We always felt that we are in such good and honest hands. I would highly recommend him- we will never be using anybody else at our home again.Well done David and thank you so much for your more
08:09 19 Jul 19
Very pleased with the work David did. Would recommend and would definitely use... more
Tahsima Habib
Tahsima Habib
14:02 18 Jul 19
David did a wonderful job on the conservatory and fencing at a property I... manage, I can only recommend him and the more
James Martin
James Martin
09:10 18 May 19
Great job installing the doors and windows. Had to be flexible, but didn’t... complain as our doors had not arrived on time. Thanks for the helpread more
N Sha
N Sha
21:12 11 May 19
David texted me the morning after I had advertised the work. He turned up the... same day. As I was describing the work that needs doing: he kept saying, Yes, I can fix that ( French sliding door), Yes, I can fix that too ( conservatory door), yes I can replace that as well ( conservatory roof). He came back to me with the quote within 1 hour. Reasonable cost. And, yes he did all the work with professionalism. I must admit I had few other window-doors and conservatory specialists...All I can say is that they should go to David for some training. David is miles ahead of anyone I had around, in every aspect. I strongly recommend David - do not waste time with anyone else if Dave is available...and boy, he is not only smart and experienced but hard working and kind,too. Well done Dave, God Bless and keep up the good work!read more
Nadeem & Syma Haque
Nadeem & Syma Haque
00:44 31 Mar 19
David provided me with a great all round experience for this job. His... communication and knowledge of the trade was brilliant. He provided me with a very competitive quote in quick time and was able to complete the job pronto. His take pride in his work which means his finishing is to a high standard. A very respectful and honest guy who provided is a great customer service. Overall a high quality piece of work and I would definitely recommend using David again in the future. Thanks!read more
Alan Martin
Alan Martin
20:21 28 Feb 19
Did a superb job fitting a cat flap in a glass panel, at a very reasonable... price. Punctual, polite and friendly, I would absolutely book again in a heartbeat!read more
jwalant patel
jwalant patel
19:35 06 Feb 19
Excellent and quick service. I posted a job on Rated people, and he provided a... quick response regarding my broken conservatory door. He offered a competitive quote and completed the work on time. I will definitely use his service in future and highly recommend others as more
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