We often get asked – are sliding sash windows energy efficient? The answer is yes. Modern sash windows combine the classic look of traditional designs with excellent thermal performance.
Today’s uPVC sliding sash windows offer significant improvements over old single glazing timber windows, but crucially, they still maintain the authentic appearance that makes them so appealing.
We’ve written this piece to explain exactly how that is possible, and what our sliding sash windows could offer to your property.
The Dilemma for Period Property Owners
If you own a Georgian or Victorian property in London or elsewhere in England, you might feel caught between preserving your home’s character and improving its energy efficiency. The sliding sash windows that give these properties their timeless elegance were originally designed without focusing on efficiency, and draughts were accepted.
Nowadays, these windows force high energy bills upon homeowners and are prone to condensation, which inevitably leads to mould and other window issues.
Despite this, homeowners worry that replacing original wooden sash windows will harm their property’s authenticity, especially in conservation areas where maintaining period features is often required. The good news is that modern sash window technology has evolved to solve this problem.
Authentic Design: Keeping the Traditional Look
At Aim Windows, our uPVC sliding sash windows are carefully designed to mimic traditional timber windows in every detail. We understand that authenticity matters, especially for period properties where the windows are a key part of the building’s character.
Our sliding sash windows feature:
- Traditional sliding mechanisms – the same up and down movement as original sash windows
- Authentic-looking sash horns that run seamlessly with the shape of the window
- Deep bottom rails that convincingly mimic Victorian-era timber windows
- Mechanical joints rather than visible welds, giving a more traditional timber-like appearance
- Astragal bars that create the appearance of separate panes, just like in original sash windows
- A wide range of woodgrain finishes that look just like painted or stained timber
These design features mean that from the street, it’s impossible to tell that these are modern windows rather than original wooden sash windows. This is particularly important for homes in conservation areas, where planning officers increasingly accept high-quality uPVC replacements that match the original design.
These authentic details help maintain your home’s character while bringing the benefits of modern materials.
Modern Efficiency: Cutting Heat Loss and Bills
While our sliding sash windows look traditional, their performance is anything but old-fashioned. Modern uPVC sash windows offer excellent thermal insulation that can significantly reduce your heating bills and carbon footprint.
Here’s how they improve on traditional single glazing:
- Double glazing with 24mm insulated glass units as standard
- Multi-chambered frames use air as an insulator to prevent warmth from escaping
- Warm edge spacer bars reduce heat transfer between panes
- Woolpile weather seals around the sashes prevent draughts
- Modern manufacturing techniques ensure a precise fit with no gaps
These features work together to achieve an ‘A’ energy rating and a U-value (a measure of heat transfer in windows) of just 1.4 W/m²K. In simple terms, they’re about five times more efficient at preventing heat loss than traditional single-glazed wooden windows.
With energy costs as high as they are, these windows act as a smart investment that could easily pay for themselves from the savings they provide.
The benefits extend beyond saving money on your heating bills. Better insulation also means:
- Fewer cold spots and draughts, making your home more comfortable
- Reduced condensation
- Better soundproofing from outside noise
- Improved security compared to older timber windows
For period, heritage, and conservation homeowners, these enhancements can make a real difference to comfort and running costs without compromising on the traditional look of your property.
Why Choose Aim Windows for Your Sliding Sash Windows
When it comes to installing new sliding sash windows, expertise matters. At Aim Windows, we’ve been fitting replacement windows across London for many years, with experience in period properties and conservation areas.
Our approach includes:
- Expert advice on the right windows for your home
- Detailed surveys to ensure a perfect fit
- In-house fitters (we never use subcontractors)
- Full FENSA accreditation and insurance-backed guarantees
- High-quality hardware from trusted brands
We source our sliding sash windows from leading manufacturers who use the best materials and production techniques. This means you get windows that look great and stand the test of time.
Ready For a Better Home?
Modern uPVC sliding sash windows offer the best of both worlds – authentic period looks with modern performance. They’re a practical solution for homeowners who want to preserve the character of their property while improving comfort and reducing energy costs.
Thanks to advances in design and manufacturing, today’s replacement sash windows can satisfy even the most tradition-conscious property owners. The subtle details that make traditional sash windows so appealing have been carefully preserved, while the drawbacks of old timber frames have been engineered away.
We’d love to invite you to see them for yourself at our showroom. Here, you can view and use these windows and speak to our friendly team about your needs.
For more information, or a free no obligation quote, you can call us on 0207 537 0852, email us at info@aimwindows.co.uk or use our online contact form.
Common Questions About Sliding Sash Windows
How long do modern uPVC sash windows last?
Modern uPVC sash windows are designed to last. With proper care, you can expect them to perform well for multiple decades and beyond. Unlike wooden windows, they won’t rot, warp, or need regular repainting; just an occasional clean.
Are UPVC sash windows approved for conservation areas?
Many conservation areas now accept high-quality uPVC sash windows, especially those designed to closely match original timber windows. The key is choosing windows with authentic details like run-through horns, mechanical joints, and appropriate glazing bars.
Do you offer different colour options for sash windows?
Yes, our uPVC sash windows are available in various colours and finishes. As well as classic white, we offer various woodgrain effects that realistically mimic painted or stained timber. We can also provide dual colour options, with different finishes inside and out. This allows you to maintain a traditional look from the street while choosing a different finish for your interior.