So, What Are Sash Windows?
Sash windows are one of the most recognisable and traditional styles of window found in the UK. If you’ve ever admired a Georgian townhouse or a Victorian terrace, chances are you’ve seen sash windows in their classic form. But while they’re steeped in history, modern versions of this window style now offer excellent energy efficiency, security, and durability.
In this blog, we’ll explain exactly what are sash windows, how they work, their benefits, and why they remain such a popular choice for homeowners across the country.
What Are Sash Windows?
They are a type of window made up of one or more movable panels — known as “sashes” — that slide open vertically or horizontally. The traditional sash window design features two panes of glass within a frame, with the sashes sliding past one another to open and close.
In the UK, they are most commonly associated with Georgian, Victorian, and Edwardian properties. However, modern versions have been adapted for contemporary homes, combining heritage looks with 21st-century performance.
You can see examples of modern sash windows supplied and fitted by Skyway Windows across Surrey.
How Do Sash Windows Work?
The most common type of sash window is the vertical sliding sash. This style operates using a system of weights, pulleys, or springs, which balance the weight of the sash and allow it to glide smoothly when opening or closing.
Modern sash windows often use a spiral balance mechanism rather than traditional weights and cords. This provides the same smooth functionality but allows for slimmer frames and better energy efficiency.
In addition to vertical sliders, some manufacturers offer horizontal sliding sash windows, although these are less common in UK homes.
The Key Features of Sash Windows
If you’re asking, “what are sash windows?”, it helps to understand their defining characteristics:
1. Sliding Opening Mechanism
Unlike casement windows, which open on a hinge, sash windows slide within the frame. This allows for controlled ventilation and is ideal in properties where outward-opening windows would be impractical.
2. Distinctive Glazing Bars
Traditional sash windows often feature glazing bars that divide the glass into smaller panes. While this was originally necessary due to limitations in glass-making, today it’s a design feature that preserves the period look.
3. High-Performance Materials
Modern sash windows are available in uPVC, aluminium, or timber-effect finishes. Many homeowners now opt for uPVC because they combine the traditional appearance with low maintenance and excellent energy efficiency.
Benefits of Sash Windows
There are many reasons why sash windows continue to be a popular choice across the UK:
Aesthetics
Sash windows add instant character and charm, especially to period homes or properties in conservation areas.
Versatility
Although closely associated with older homes, modern sash windows suit contemporary properties when designed with clean lines and neutral colours.
Ventilation
Their sliding operation allows for flexible airflow control without opening the window fully, which can help with security and safety.
Energy Efficiency
Modern sash windows are designed to meet high thermal performance standards, particularly when using A-rated double glazing. Learn more about energy ratings from the British Fenestration Rating Council (BFRC).
Are Sash Windows Energy Efficient?
While original timber sash windows were prone to draughts, rattling, and poor insulation, modern versions have solved these issues. Up-to-date windows now feature:
- Multi-chambered uPVC or aluminium frames for thermal insulation
- Double or triple glazing for reduced heat loss
- Weather seals to prevent draughts
- Optional acoustic glazing for sound reduction
For full compliance with energy performance standards, it’s essential to use a FENSA-registered installer. You can check the registration of trusted suppliers like Skyway Windows through the FENSA installer search tool.
Do Sash Windows Suit Modern Homes?
Yes. While they are traditionally used in older properties, they can look just as good in modern homes—especially when paired with sleek, minimal glazing bars or in a flush window style.
At Skyway Windows, we supply and fit a range of flush windows and other contemporary designs for homeowners wanting clean lines alongside traditional features.
What About Security?
Modern sash windows are fitted with secure locking systems, reinforced frames, and toughened glass, providing the same level of security as any other window style.
Options for additional security include:
- Multi-point locking mechanisms
- Key-operated locks
- Laminated or toughened glazing
Other Glazing Products to Consider
When upgrading your windows, you may also want to consider matching doors or other glazing features for a cohesive look across your home. Popular options include:
- Composite entrance doors – Strong, secure, and thermally efficient front doors.
- Aluminium patio sliding doors – Ideal for modern homes and garden access.
- Aluminium bifold doors – Perfect for open-plan living and larger openings.
Why Choose Skyway Windows for Sash Windows in Surrey?
At Skyway Windows, we provide high-quality windows for homes across Surrey and surrounding areas. We offer:
- A wide range of traditional and modern sash window styles
- Energy-efficient, A-rated products for maximum performance
- Fully FENSA-certified installations for compliance and peace of mind
- Expert advice to help you choose the right windows for your home
If you’re still wondering what are sash windows and whether they’re right for your property, contact us today for tailored advice and a free quote.
