How to choose energy-efficient windows for your home
- 15 July, 2025|
- News
In Summary
- Having a home with thermally efficient windows promises to lower energy bills
- uPVC is the UK’s most popular window frame material, largely thanks to its impressive energy performance
- Aluminium is also a high performer when it comes to thermal efficiency
- Window styles and glazing can also work to lower your energy bills, reduce your carbon footprint, and lead to a more comfortable home environment.
- Warwick Development offers uPVC and aluminium windows in modern styles, such as standard casements, traditional sliding sash, and contemporary flush sash designs.
Recent studies have reported that UK homeowners are increasingly prioritising energy efficiency when searching for replacement windows.
The reasons for this are plentiful.
Firstly, in today’s uncertain economic climate, energy efficient windows successfully reduce energy bills, as well as increasing the comfort of your living space and lowering your carbon footprint – with sustainability rightfully a key priority for homeowners too.
In this blog, we’ll explore how thermally efficient windows achieve these benefits and highlight a selection of uPVC and aluminium products that can help you create a more comfortable, valuable, and environmentally responsible home.
uPVC can be finished to replicate the appearance of timber.
Why Thermally Efficient Home Improvements Matter
As mentioned in the introduction, improving your home’s thermal efficiency goes beyond comfort – it’s about energy use, sustainability, and saving money.
Choosing energy-efficient windows can significantly improve your home’s performance and value, ensuring your initial investment is repaid overtime.
Reduced Heat Loss
Well-insulated windows reduce unwanted heat transfer. This keeps your home warmer in winter and cooler in summer, cutting down your reliance on costly central heating or air conditioning.
Lower Energy Bills
Less energy use means lower monthly bills. Thermally efficient windows reduce heat loss, which directly impacts your energy consumption.
Improved Environmental Impact
Energy-efficient windows reduce your carbon footprint. By limiting the need for heating, you lower greenhouse gas emissions, giving you peace of mind that you’re investing in a more sustainable living environment.
Increased Home Value
As aforementioned, thermally efficient homes are in high demand. Having a sustainable property will lead to a higher valuation if you ever choose to sell or relocate.
Sliding windows are brilliant for increasing ventilation
Thermally Efficient Window Materials
uPVC Windows
uPVC (unplasticised polyvinyl chloride) is a durable plastic material and the UK’s most popular window frame choice (as well as being popular for doors, cladding, and pipes). It’s renowned for being low-maintenance, long-lasting, and highly customisable, available in a range of colours and finishes (even woodgrain effects) to match any property style.
uPVC windows achieve their thermal performance through multi-chambered profiles, which trap pockets of air to reduce heat transfer. When paired with high-performance glazing and weather seals, they can achieve A-rated energy efficiency levels.
Aluminium Windows
Aluminium is a lightweight yet strong metal known for its sleek aesthetics and durability. While traditionally less insulating than uPVC, modern aluminium windows feature advanced thermal break technology. A thermal break is a layer of insulating material that separates the inside and outside aluminium frames, stopping heat from passing through.
At Warwick Development, aluminium windows meet and exceed all building regulation requirements and achieve A-ratings for thermal efficiency. Their slim sightlines allow for larger glazing areas (enabling more natural light to enter the home), while maintaining excellent performance.
Aluminium windows are an excellent choice for a modern aesthetic
Other Factors That Improve Your Windows’ Thermal Efficiency
Glazing
Glazing plays a vital role in how energy efficient your windows are. Double glazing is now commonplace (installed in around 90% of UK homes), using two panes of glass with a gap filled with air or argon gas for insulation.
Triple glazing goes a step further, adding a third pane of glass. This helps to:
- Further reduce heat loss
- Improve noise insulation
- Increase security
Fact: Triple glazing can reduce heat loss by up to 40% compared to standard double glazing.
Window Style
The design of your windows can also affect performance. Some styles offer better sealing and lower air leakage:
- Casement windows: Known for their tight seal when closed
- Flush sash windows: Sit flush against the frame for a sleek, draft-resistant fit
- Vertical sliders: Modern sash windows use weather-tight seals for improved performance
- Tilt and turn: Excellent for ventilation and energy efficiency
Choosing the right style ensures minimal draughts and maximises the thermal efficiency of the frame and glazing combination.
Thermally Efficient Windows from Warwick Development
At Warwick Development, both uPVC and aluminium windows are designed for outstanding thermal performance and customisation.
uPVC Windows
- Available styles: Casement, Flush Sash, Vertical Sliders, Tilt & Turn
- Multi-chambered profiles for excellent insulation
- High security locking systems
- A choice of attractive finishes, including realistic woodgrain effects
Example: Eurocell PVCu casement windows can achieve U-values as low as 0.8 W/m²K and are made from 100% recycled materials.
Aluminium Windows
- Available styles: Casement, Flush, Heritage, Fixed Light
- Thermal break technology and A-rated performance
- Over 200 RAL colour options, including woodgrain and marine-grade finishes
- PAS 24 accredited and BS Kitemarked for security
Highlight: Aluminium flush casement windows achieve an A+ rating in the BRE Green Guide and U-values as low as 1.4 W/m²K.
Whether you’re a homeowner or a trade professional, Warwick Development’s windows are designed to meet all thermal efficiency needs while looking fantastic.
Aluminium windows have thermal break technology to reduce heat transfer.
Who Are Warwick Development?
We’re Warwick Development — a family-run company based in Sheffield with over 30 years’ experience making and fitting uPVC and aluminium windows and doors. From here, we work with homeowners and tradespeople across Sheffield and the surrounding areas.
Whether you need something low maintenance, with great energy ratings to keep cold air out, or a modern look with clean lines and larger glass panels, we’ve got options to suit all kinds of homes — from period properties to new builds and extensions.
We offer a wide range of colours and finishes, including aluminium with powder coating and woodgrain effects, so you can get the style you want without the hassle of regular painting.
If you want to know more or just have a chat about what might work for your home, pop into our showroom, give us a ring on 0114 257 1200, or send us a message online. We’re happy to help you figure out the best windows for your needs.
What We Offer
- Bespoke uPVC and aluminium windows
- Wide range of colours and window styles
- Colour and finish customisation
- High security locking and thermal performance
Why Choose Warwick Development?
- Over 25 years of industry experience
- FENSA-registered installations
- PAS 24 security accreditation
- Products meet and exceed building regulations
- Excellent customer reviews and trade partnerships
Quickfire FAQs
What’s the most energy-efficient window material?
Both uPVC and aluminium (with thermal breaks) offer excellent efficiency when installed properly.
Are flush sash windows energy efficient?
Yes, they sit tight within the frame and reduce draughts.
Does triple glazing make a big difference?
Yes, it significantly lowers heat loss and improves acoustic insulation.
Are uPVC frames really low maintenance?
Yes, uPVC frames need little upkeep, making them a perfect choice for homeowners wanting durable, hassle-free windows.
Can I get larger panes of glass for more natural light?
Absolutely! Aluminium’s strength makes it ideal for holding larger glass panes, perfect for modern homes and extensions wanting a minimalist design and contemporary look, with the mental and physical health benefits of being exposed to more natural light clear.
Do you provide expert advice for choosing the right windows?
Yes, we’re always happy to talk with you and help you understand the key differences between types of windows to find the best choice for your specific needs. Feel free to give us a call!
Are aluminium windows suitable for extreme weather conditions?
Definitely — aluminium with powder coating is built to withstand harsh weather while maintaining an attractive option and modern appearance.
What colour options are available?
We offer a wide variety of colours, including popular anthracite grey and woodgrain finishes, perfect for both traditional homes and contemporary style.