A-rated Windows vs Standard: Energy Savings Comparison
Every winter, millions of UK homeowners unknowingly waste hundreds of pounds through their windows. Poor window energy efficiency doesn’t just affect your wallet – it creates cold spots, draughts, and uncomfortable living spaces.
The difference between A-rated windows (like our wood-effect Timberlook windows) and standard alternatives can mean the difference between comfortable, affordable heating and constantly battling high energy costs.
Whether you live in a modern home or a period property, the right windows can transform both your comfort levels and your energy bills.
A close-up of Irish Oak effect flush sash windows, embracing the warmth and charm of a brick exterior.
What do window energy efficiency ratings mean?
Window energy ratings are standardised measurements that indicate how well a whole window performs thermally. The British Fenestration Rating Council (BFRC) developed this system to help homeowners easily compare different window and glazing options. The rating scale runs from A+ (most efficient) down to G (least efficient).
Windows are rated based on several factors:
- U-value – Measures how much heat is lost through the window frame and glazing
- Solar gain – How much free heat from sunlight passes through into the home
- Air leakage – The amount of heat lost through draughts
A lower U-value means better insulation, with A-rated windows typically achieving U-values between 0.8-1.2 W/m²K, compared to older single glazing which can be as high as 5.0 W/m²K.
What does this mean in terms of your home’s overall thermal efficiency?
The impact of thermal efficiency on your energy bills
Because heat loss through windows accounts for around 18% of total heat loss in a typical home (according to GOV.UK), poor thermal efficiency in windows directly translates to higher heating bills.
Investing in quality double glazed windows (like those we offer at Timberlook!) means that you can enjoy lower heating bills, a smaller carbon footprint and a more comfortable living space.
What are A-rated windows?
The rating scale developed by the BFRC ranks windows from A+ down to G, with A+ being the most thermally efficient windows available on the market.
A-rated windows offer excellent thermal efficiency, achieving this through innovative engineering, including:
- High-performance double glazing with low-emissivity coatings and inert gas fills between panes
- Insulating frames with air pockets (in uPVC frames) or thermal break technology (in aluminium windows) that prevent heat transfer
- Precision manufacturing eliminating thermal bridges that allow heat to escape
- Weather sealing that prevents draughts
Is uPVC a good option for A-rated windows?
uPVC has become a popular material due to its excellent insulating properties and cost-effectiveness. Modern uPVC window frames feature multi-chambered designs that trap air, providing insulation while maintaining structural strength.
This thermal efficiency comes at a fraction of the cost of materials like timber or aluminium frames, making uPVC an affordable way to achieve A-rated energy performance without compromising on quality or durability.
A detailed view of a green flush sash window, reflecting the surrounding landscape, showcasing its elegant design.
Why choose A-rated windows over A+?
A+ windows are the most thermally efficient windows available, however it’s important to understand that these will likely come with a much higher price tag due to the engineering (usually involving triple glazing) needed to achieve this rating.
Because of this, upgrading to new A-rated windows is an ideal option for most homeowners, offering excellent thermal efficiency at a price that is feasible when replacing old windows.
Comparing A-rated windows to B and C-rated alternatives
The differences between window ratings becomes clear when looking at the range of U-values between each rating. A-rated windows offer better performance than B, C, D, E, and G-rated windows.
A-rated windows
U-values between 0.8-1.2 W/m²K
B-rated windows
U-values between 1.2-1.4 W/m²K
C-rated windows
U-values between 1.4-1.8 W/m²K
Over the long term, the energy savings from A-rated windows typically offset their higher initial cost, making them a smart long-term investment.
Introducing Timberlook: combining energy efficiency with heritage design
Choosing thermally efficient windows shouldn’t mean having to sacrifice on style!
Our Timberlook wood-effect uPVC windows offer the perfect combination of beautiful heritage-inspired aesthetics with A-rated efficiency.
Our expertly crafted windows replicate the authentic look of 19th-century timber flush sash windows while delivering A-rated thermal performance with U-values as low as 1.2 W/m²K.
Unlike timber, they don’t require sanding, staining or repainting. Our low-maintenance uPVC windows are incredibly durable, providing lasting beauty without the maintenance of real timber.
A striking black flush sash window set against a white brick wall, offering a modern contrast and elegant design.
A-rated efficiency, beautiful heritage style
At Timberlook, we poured years of experience and knowledge into creating the perfect uPVC timber alternative window, ensuring it provides beautiful aesthetics while meeting modern demand for thermal efficiency.
Authentic joints
Using innovative Timberweld technology, each of our windows features realistic mortise and tenon joints without the diagonal welds that are usually a telltale sign of uPVC windows.
Flush sash fit
Our Timberlook range features an elegant flush sash (where the sash sits completely level with the outer frame when closed). This replicates historic timber window design.
Concealed trickle vents
Our window range features concealed trickle vents that maintain the heritage aesthetic while meeting current building regulations for ventilation.
Flush door system
Alongside our beautiful window range, we also offer a range of timber-effect doors, available in both single and elegant French doorsets.
Colours & wood-effect finishes
Available in a wide range of authentic woodgrain finishes including popular anthracite grey and light oak effects, plus standard and dual-colour options to match any property style.
Modern or traditional hardware
Choice of contemporary or traditional heritage hardware including period-appropriate handles such as Peardrop and Monkeytail designs.
Choosing the perfect new windows for your home
Whether you’re renovating a period property or simply love classic design, our Timberlook flush sash windows prove you can have both exceptional energy efficiency and timeless elegance – all at a more affordable price point than traditional timber alternatives. Our timber-effect windows aren’t just a great option for owners of period properties – they are also incredibly popular with homeowners looking to add charm and character to contemporary homes!
A modern grey flush sash window installed into a contemporary home façade.
Boost your home’s energy efficiency with A-rated windows from Timberlook
Whether you’re looking to reduce your heating bills, improve comfort, or find the perfect heritage-inspired windows, we’re here to help you find the perfect solution.
We have a nationwide network of trusted Timberlook specialists ready to transform your home with beautiful, thermally-efficient replacement windows. To find a Timberlook installer in your local area or to learn more, please get in touch by completing our online contact form or calling us on 01253 888 222.
