Sliding Sash Windows That Keep the Look of Timber
Sash windows are a timeless classic, commonly found in period properties and equally at home on contemporary houses. Eurothermal uPVC sash windows replicate the authentic charm of timber without the upkeep. In realistic woodgrain finishes they give you the beauty of real wood with the durability and low maintenance of uPVC.
Designed for performance and practicality, our A rated energy efficient sash windows glide smoothly on spring balances and tilt inwards so you can clean the outside glass from inside the room. Every window is made to measure and fitted by our FENSA certified team with a full product and installation guarantee. We replace sash windows across Hayes, Hillingdon, Uxbridge, Southall and Yeading.
uPVC sash windows
- Realistic woodgrain finishes copy painted timber without the repainting, rot or sticking sashes
- Spring balances let both sashes glide up and down with very little effort
- Tilt in sashes let you clean the outside glass safely from inside, even upstairs
- A rated double glazing and weather seals keep heat in and draughts out
Period detailing and security
- Sash horns, Georgian bars and astragal style bars recreate original Victorian and Edwardian detailing
- Made to measure to your existing opening, because period frames are rarely square or standard
- Multipoint locking and restrictors keep every sash secure while still allowing safe ventilation
- FENSA certified fitting with a full guarantee gives proof of compliance and lasting cover
01 / Windows
How uPVC Sliding Sash Windows Work
A sash window slides vertically within its frame rather than swinging outward. Traditional timber sashes have been fitted in English homes since the 1670s and hold their position using cords and heavy weights hidden in the frame. Modern uPVC sashes do the same job with spring balances, so the frame can be slimmer and there is nothing to snap or rot.
- Spring balances hold each sash at any height and make opening and closing easy
- Brush seals along the running surfaces keep the sashes sliding smoothly and cut draughts
- Both sashes slide, so you can open the top for warm air to escape or the bottom for fresh air
- Tilt in action lets the sashes fold inward for cleaning the outside glass from inside
- Lift hooks or pull handles in period or modern styles let you open each sash easily
02 / Windows
uPVC Sash Windows vs Timber Sash Windows
Both have their place, and we will tell you honestly which suits your property.
| uPVC sash | Timber sash | |
|---|---|---|
| Upkeep | Wipe clean, no painting | Repainting every few years, and sashes can stick when wood swells |
| Typical cost | Roughly £500 to £1,200 per window fitted | Roughly £1,200 to £3,500 per window fitted |
| Look | Convincing with woodgrain foil, bars and horns | The original material and finish |
| Draughts and insulation | Multichamber frame, double glazing and modern seals | Excellent when well made, but older frames can rattle and leak |
| Conservation areas and listed buildings | Often not accepted | Usually expected and easiest to get approved |
03 / Windows
Sash Window Details That Make the Difference
On a period home the small details decide whether a new window looks right or looks like a replacement.
- Sash horns, the small projecting joint at the base of the top sash, recreate the traditional Victorian and Edwardian look
- Georgian bars and astragal style bars copy the glazing pattern of original sashes
- Woodgrain foils in white, cream, oak and heritage tones, plus smooth finishes for a painted look
- Dual colour options with a colour outside and white inside to match your interior
- Slim sightlines and a proper bottom rail that follow the proportions of the windows you are replacing
04 / Windows
Replacing Box Sash Windows Is a Specialist Job
Most period sash windows sit in box frames that are rarely square and never quite the same size twice. That is why replacing them properly takes a survey, careful measuring and a qualified installer, not an off the shelf window.
- A technical survey records the true size and shape of every opening before anything is made
- Each window is made to measure so the proportions, bars and horns match what was there
- Old sashes, cords and weights are removed and the new window is fitted square and sealed
- Plaster and finishes are made good, and you receive a FENSA certificate when we are done
05 / Windows
Sash Windows in Conservation Areas and Listed Buildings
If your home is listed or in a conservation area, check before you order. The rules depend on your property and your council, and a wrong choice can mean being asked to replace the windows.
- Listed buildings always need listed building consent, and uPVC is almost never accepted on a listed frontage
- Some conservation areas have an Article 4 Direction, which means even like for like replacement needs planning permission
- Where there is no Article 4 Direction, an unlisted house can often have replacement windows that look similar to the originals
- Councils sometimes accept uPVC sashes where the street already has them, but timber is the safe expectation
- Hillingdon has a number of conservation areas, so confirm with the council before we survey
We will tell you honestly if uPVC is unlikely to be approved for your property, rather than take an order we cannot stand behind.
06 / Windows
Draughts, Noise and Safe Ventilation
- Modern uPVC sashes use double glazing, brush seals and a tight fit, which is far better than old single glazed timber sashes
- Sliding sashes rely on brush seals, so a casement window is usually slightly more airtight, though a well fitted sash performs well
- Double glazing reduces noise from busy roads, rail lines and aircraft, which matters in parts of Hayes, Southall and Hillingdon
- Restrictors limit how far a sash opens, keeping children safe while still letting fresh air in
- A sash only opens by half its height, so for a bedroom escape window we check the clear opening size, and a side hung casement is often easier to make compliant
07 / Windows
Sash Window Installers Near You in Hayes
Eurothermal Glazing is based at 25 Chaucer Avenue, Hayes, Middlesex, UB4 0AP. We replace sash windows across Hayes, from Hayes Town, Botwell, Hayes End and Wood End to Yeading, and throughout West London, including:
- Hayes UB3 and UB4
- Southall UB1
- Norwood Green UB2
- Northolt UB5
- Greenford UB6
- West Drayton UB7
- Uxbridge UB8
- Denham UB9
- Hillingdon UB10
If you cannot see your area, call +44 7555 398335 and we will confirm coverage before booking your free survey.
How It Works
From your first enquiry to installation and aftercare, we keep each stage clear and straightforward.
About Us-
1
Tell Us About Your Project
Tell us what you want to replace or install and where the property is located.
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2
Technical Survey
Where required, we measure the openings and assess the practical requirements of your property.
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3
Confirm Your Specification
Choose the frame material, glazing, opening style, colours, finishes and hardware.
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4
Made to Measure
Your selected windows or doors are produced to the agreed dimensions and specification.
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5
Installation & Aftercare
Our team completes the installation, checks the finished system and remains available for aftercare.
Frequently Asked Questions
Ask Us a QuestionHow do uPVC sliding sash windows work?
A uPVC sliding sash window has two sashes that slide up and down within a frame. Spring balances inside the frame counterbalance the weight, so each sash holds at any height without the cords and weights used on traditional timber sashes. Our sashes also tilt inwards for easy cleaning.
How much do uPVC sash windows cost?
Independent UK price guides put a fitted uPVC sliding sash at roughly £500 to £1,200 per window, depending on size, colour and detailing, compared with roughly £1,200 to £3,500 for timber. Woodgrain and coloured finishes cost more than white. These are national guide figures, not a Eurothermal quote, so book a free survey for an exact price.
Are uPVC sash windows allowed in conservation areas?
Sometimes, but it depends on your property and your council. Listed buildings need consent and rarely accept uPVC, and conservation areas with an Article 4 Direction need planning permission even for like for like replacement. Check with your local planning authority before ordering, and we will tell you honestly if uPVC is unlikely to be approved.
Do I need planning permission to replace sash windows?
On an unlisted house in England, replacement windows that look similar to the originals usually do not need planning permission. You do need it if an Article 4 Direction applies, and listed buildings always need listed building consent. The work must also meet Building Regulations, which a FENSA certified installer certifies for you.
Are sash windows draughty or do they rattle?
Old timber sashes often were, but modern uPVC sashes are built with double glazing, brush seals and a snug fit, so they should not rattle or leak noticeably. A sliding sash is usually slightly less airtight than a casement because it relies on brush seals, though a well fitted window still performs well.
What are sash horns?
Sash horns are the small projecting details at the base of the top sash on Victorian and Edwardian windows. They were originally a strengthening joint and are now a decorative feature that keeps the authentic period look on a uPVC sash.
How do I clean sash windows from inside?
Our uPVC sashes tilt inwards, which lets you clean the outside glass from inside the room. This is particularly helpful for upstairs windows that are awkward to reach from outside.
Can a sash window be used as a fire escape?
It depends on the clear opening. A sash only opens by half its height, so the usable opening is smaller than the window itself. For bedrooms that need an escape window, we measure the clear opening, and a side hung casement is often the easier option to make compliant.