When you’re shopping for new windows, you’ll spot a colourful sticker on the glass that looks a bit like the label on your fridge or washing machine.
That’s the window energy rating, and it tells you exactly how well a window will keep your home warm, your energy bills low and your living spaces comfortable all year round.
Understanding energy ratings on windows is one of the smartest things you can do before investing in replacement windows, and at Northwich Glass, we always recommend choosing A-rated windows for the very best performance.
With over 60 years of experience helping homeowners across Cheshire, we’ve seen firsthand how the right windows can transform a property’s warmth, comfort and overall value.
Explaining energy ratings on windows: What to look out for
In the UK, window energy ratings are issued by the British Fenestration Rating Council (BFRC), and you’ll often see them displayed on a colourful WER rainbow label, similar to those found on white goods.
The label ranks windows from A++ down to E, based on how much heat is retained, how much air leakage occurs and how much solar gain (heat from sunlight) the window allows in.
Here’s a quick breakdown of what each rating means:
| Energy rating | What it means |
| A++ | The very best performance ratings available, maximum thermal efficiency and minimal heat loss, not many windows have this at present |
| A+ | Excellent energy efficiency, well above modern standards |
| A | High-performing efficient windows offering great energy savings |
| B | Good performance, meets minimum standards |
| C | The minimum window energy rating of Band C is required under UK Building Regulations for new installations |
| D & E | Older or lower-performing window products, often found in older homes or single glazing. |
The rainbow labels make it easy to compare different window products at a glance, helping you make a confident choice.
What makes an energy efficient window?
Windows actually have a lot of disparity in the way that they are constructed, which explains the vast range in their energy performance.
The window frame matters enormously. We recommend uPVC or modern aluminium because both materials offer fantastic insulation and won’t change shape, or even fall victim to insect damage which can often be the case with timber.
Next comes the glazing. Our double glazing features two panes of glass with a sealed gap in between filled with argon gas. Argon is denser than ordinary air, so it slows down heat transfer dramatically, with its potential to lower your energy bills being the reason we choose it. In simple terms, the warmth from your radiators stays inside rather than escaping through the glass, while cold air from outside struggles to get in. This is exactly what improves your home’s energy efficiency.
Add in low-emissivity coatings to control solar heat gain and tight seals to prevent air leakage, and you’ve got a window that works hard all year round.
What are the benefits of an energy efficient window?
Choosing A-rated windows brings a host of benefits that go well beyond a tidy-looking home.
Lower energy bills
Because efficient windows reduce heat loss, your boiler doesn’t need to work as hard. That means noticeable energy savings month after month, a real bonus given how much heat older windows allow to escape. It’s natural to think of these savings as being exclusive to winter, but the good news is that you’ll benefit in summer too. Tight seals prevent unwelcome heat entering, especially beneficial on hot nights as you won’t need to run a fan all day long.
More sustainable home
Less energy used means a smaller carbon footprint. If you’re keen to live more sustainably, upgrading from old windows is one of the most impactful changes you can make.
Natural comfort
No more cold draughts or chilly spots near the window. A-rated windows let in plenty of visible light while keeping unwanted heat out in summer and warmth in during winter.
Increased property value
Buyers love a home that’s already been upgraded. Modern, energy-rated windows can genuinely add to the value of your home, and can be used as a major selling point should you ever wish to list your property.
Acoustic insulation
The same construction that traps heat also dampens sound. Living near a busy road? Double glazing makes a huge difference to noise levels.
What type of energy efficient window is available to me?
The great news is that you don’t have to compromise on style to get top-tier thermal efficiency. At Northwich Glass, every window we install is A-rated as standard.
Window styles
Casement windows
A very simple window that you likely use everyday already. They are hinged form the side or top, and open inwards or outwards depending on the option you choose. The UK’s most popular style.
Flush sash
Flush sash windows sit perfectly flat within the frame, providing a clean, traditional appearance that suits both period and modern properties.
Sliding sash
The glass sash slides up and down, this is a historic style that’s been popular in this country for centuries. If getting plenty of fresh air is your priority, sliding sash windows are a great pick.
Bay & bow
Bay and bow windows project outwards from the wall, creating more space inside and flooding your room with natural light.
Tilt & turn
Tilt & turn windows open in two ways, tilting inwards from the top for ventilation or swinging fully open for easy cleaning.
Window materials
uPVC
uPVC is a durable, low-maintenance synthetic material that offers brilliant insulation and a wide range of colours and finishes (including convincing woodgrain effects). It’s affordable, long-lasting and the most popular choice for British homes.
Aluminium
Modern aluminium frames are slim, strong and incredibly sleek. They’re perfect for contemporary homes and allow for larger panes of glass, letting in more light without sacrificing thermal performance.
Energy efficient windows from Northwich Glass
Every window we supply is designed to be A-energy rated, meaning you can rest easy knowing your home will be warmer, quieter and cheaper to run. Our range covers casement, flush sash, sliding sash, bay & bow and tilt & turn styles, all available in uPVC or aluminium and a wide selection of colours and finishes to match your home.
We work with industry-leading suppliers, including Rehau, Residence Collection and Kommerling, and we back every installation with a 10-year warranty for complete peace of mind.
Who are Northwich Glass?
Founded in 1959, we’re a family-run business based in Northwich, serving homeowners across Cheshire. With over 60 years in the glazing industry, we’ve built our reputation on quality products, expert installation and genuine, no-pressure service.
We’re FENSA accredited and a proud member of Which? Trusted Trader, so you know you’re in safe hands from your first enquiry through to the final fitting. Our friendly team includes experienced designers, dedicated project managers and skilled fitters who’ll make sure your installation runs smoothly with minimal disruption.
You’re more than welcome to pop into our showroom at Leicester Street, Northwich, CW9 5HW to see our full range up close. We’re open Monday to Thursday 8am-5pm, Friday 8am-4pm and Saturday 9am-1pm.
Ready for a free estimate on A-rated replacement windows? Give us a call on 01606 810 000, email reception@northwichglass.co.uk or fill in our online contact form. We’d love to help you find the perfect windows for your home.
