Are you choosing the most energy efficient windows?

The biggest shift in the home improvements industry, and most others, in the past few years has undoubtedly been the rise of sustainability and energy efficiency.

With rising energy bills and the added emphasis on reducing emissions for the overall health of our planet, we’re increasingly looking at how we can make our homes as self-sustaining as possible.

Windows are often the first port of call when it comes to achieving this. They play a really important role in sealing air gaps and reducing heat transfer, which means you’ll have less need to use radiators and heating appliances if you choose the right ones.

uPVC and aluminium frame materials, combined with modern double/triple glazing are the best ways to achieve this, for a more affordable, healthier home. We’ll explore the best options in your quest to find the highest rated energy efficiency windows in this blog.

What are the benefits of choosing the highest rated energy efficient windows?

In simple terms, energy efficiency is about how well your windows keep warm air in during winter and stop too much solar heat from getting in during summer. The less heat transfer through your windows, the less your boiler has to work and the lower your heating bills.

It’s measured by something called a U-value (the lower the number, the better) and a Window Energy Rating from the British Fenestration Rating Council, with ‘A’ being one of the top grades.

Lower energy bills

Old double glazing or single glazing can let a surprising amount of heat escape. According to the Energy Saving Trust, replacing single-glazed windows with energy-efficient double glazing could save a typical semi-detached home around £140 a year on energy costs.

Multiply that over a decade, and the savings really add up.

A more comfortable home

Modern energy efficient windows reduce draughts, eliminate cold spots near the glass and offer noise reduction from busy roads. You’ll notice the difference the moment you walk in.

A healthier home

Better insulation means less condensation on the inside of your panes of glass, which helps prevent damp and mould. Many of our windows also filter out harmful UV rays so your furniture and flooring don’t fade in natural light.

A more sustainable home

Lower energy consumption means a smaller carbon footprint. With our planet needing help now more than ever, it’s a really good way to help out.

What makes the highest rated energy efficient windows stand out?

Here’s what separates the best windows from the rest, and how you can find the best option for your home.

Energy ratings

We recommend looking for A-rated windows, as the initial slightly higher investment will repay itself with lower bills over time and an increase to your property value.

This rating, issued by the British Fenestration Rating Council, takes into account thermal performance, solar heat gain coefficient and air leaks. All of our glazing achieves an ‘A’ energy rating as standard.

Glazing technology

The type of glass really matters.

We use advanced double glazing with each of our windows, which features two panes of thermal glass, argon gas filling between them and a spacer bar. The argon gas centre promises to slow down heat loss far better than ordinary air. Triple glazing is also available for those who want the very highest thermal efficiency.

Frame materials

Your frame material plays a huge role in your home’s energy efficiency. uPVC windows have multi-chamber profiles that trap warm air, while modern aluminium frames use thermal breaks to keep cold out. Both are a great choice depending on your style and your home’s needs.

Installation quality

Even the best windows will underperform without proper installation. A perfect fit is essential because gaps cause draughts and energy loss. Professional installation by a FENSA registered company like ours guarantees compliance with UK building regulations and gives you genuine peace of mind.

What are the highest rated energy efficient windows on the market?

Let’s break down your two main choices. Every option, regardless of style/material, is available with both double and triple glazing.

Window materials

The frame material affects everything from looks to longevity to thermal performance.

uPVC

uPVC stands for unplasticised polyvinyl chloride, a sturdy, weatherproof synthetic material that has been used in UK windows since the 1980s. You can’t walk down an Essex street without spotting uPVC windows, because they’re the UK’s most popular frame material by a mile.

That doesn’t mean that every home has to look the same, however. Modern uPVC is available in multiple finish types, including convincing woodgrain effects and contemporary classics like anthracite grey, chartwell green and heritage cream. Dual colour options are available.

Benefits of uPVC windows:

• Superb thermal insulation thanks to multi-chamber profiles
• Low maintenance (no painting, no rotting)
• Cost-effective without compromising quality
• Wide range of colour options and woodgrain effects

Aluminium

Aluminium windows have surged in popularity for their slim, modern appearance. Strong yet lightweight, aluminium allows for larger panes of glass and slimmer sightlines, meaning more natural light flooding into your home. Today’s aluminium frames feature thermal breaks (an insulating barrier inside the frame) that deliver high performance comparable to uPVC.

Benefits of aluminium windows:

• Slim sightlines that maximise glass area
• Incredibly strong and corrosion-resistant
• Full RAL colour range including anthracite, black and metallic finishes
• Ideal for contemporary window design
• Long lifespan with minimal upkeep

Window styles

The right window style depends on your property type, your taste and how you want the window to function.

Casement windows

Casement windows are the most common window type in the UK, largely because of how simple and reliable they are. They open on a single hinge, whether it be at the top of the sides of the frame, and can open both inwards and outwards.

• Wide opening for excellent ventilation
• Tight seal when closed for excellent insulation
• Available in uPVC and aluminium

Flush casement

A flush casement window sits perfectly level with the frame when closed. You can run your fingers across the exterior and be greeted with a perfectly smooth feel. It looks brilliant and is really popular with buyers, without compromising on any of the performance expected from standard casements.

• Heritage aesthetic with modern thermal performance
• Optional Georgian or astragal bars
• Looks like timber without the maintenance

Sliding sash

Our uPVC sliding sash windows feature two vertically sliding sashes, perfect for Victorian and Georgian properties but also new builds looking for a traditional touch. They’ve been popular for centuries, something that looks unlikely to change.

• Classic period look
• Tilt-in function for safe cleaning
• Brilliant ventilation control

Bay windows

Bay windows project outwards from the wall, creating a pocket of extra space inside and a striking exterior feature.

• Floods rooms with natural light from multiple angles
• Adds character and kerb appeal
• Available in uPVC and aluminium

Tilt and turn

A clever dual-function design: tilt the window inwards from the top for secure ventilation, or turn it fully inwards for easy cleaning.

• Brilliant for upper floors and apartments
• Excellent airtightness and thermal efficiency
• Single handle controls both functions

Energy efficient windows in Essex and East London from Advanced Glazing Systems

We supply and install every window style mentioned above in both double glazing and triple glazing across Essex and East London. Whether you’re after classic white uPVC casement windows, anthracite grey aluminium tilt and turn windows or a sliding sash style in chartwell green, we’ll help you find the perfect fit.

Every window we install includes:

• A-rated thermal performance with U-values as low as 0.8 W/m²K
• Sealed units with argon gas fills and warm edge spacers
• Multi-point locking systems conforming to BS7590 (PAS011)
• Galvanized steel reinforcement for added strength
• A wide range of colours, hardware and customisation options

We’re proud to be Secured by Design accredited, which means our windows meet police-approved security standards.

Who are Advanced Glazing Systems?

We’re a family-run business founded in 2004. We really believe that choosing a local installation company is beneficial for our clients, as not only do we offer a personal service, but local expertise that can’t be matched by nationwide chains (especially when it comes to things such as conservation areas).

We install windows, doors, conservatories, orangeries, roof lanterns and more across Essex and London, with accreditations including FENSA, Which? Trusted Trader and Secured by Design. Every installation comes with our comprehensive 10-year warranty, which is really good for your peace of mind.

Ready to start saving on your heating bills? Call us on 01277 230101 or email sales@advancedglazingsystems.co.uk for a friendly, no-pressure chat about your window replacement project.

FAQs

How long do energy efficient windows last?

Quality uPVC windows typically last 25–30 years, while aluminium windows can last even longer. We back ours with a 10-year warranty for total peace of mind.

Will new windows really lower my energy bills?

Yes. Replacing old double glazing or single glazing with A-rated windows can deliver noticeable energy savings every year, plus a warmer, quieter home.

In summary

• The highest rated energy efficient windows reduce heat loss, lower energy bills and shrink your carbon footprint
• Look for A-rated windows with low U-values
• uPVC and aluminium are both brilliant frame materials with different aesthetic strengths
• Glazing technology like argon gas fills and warm edge spacers makes a real difference
• Advanced Glazing Systems offers expert installation across Essex and London, backed by a 10-year warranty and 100% customer satisfaction record