Llantwit Major · South Glamorgan
Sash Windows in Llantwit Major
Our glaziers survey sash windows across Llantwit Major, recording mouldings, horns and glazing bars so the new windows suit the house and any conservation requirements.
- CF61
- Guide from £1,495
Replacement sash windows in Llantwit Major
Security on sash windows comes from keyed sash locks at the meeting rails, sash stops that limit the opening for ventilation and child safety, laminated glass, and close-fitting staff and parting beads. Ground-floor sashes in older houses are often the weakest point, so locks are worth upgrading during replacement.
Heavy double glazed sashes need matching weights. When single glazed sashes are swapped for double glazed ones in an existing box, the old weights are usually too light, so the glazier re-weighs each sash to stop it dropping or creeping up, and checks the pulleys can carry the load.
Sash windows can be supplied as complete new frames, or as new double glazed sashes fitted into an existing sound box frame. Keeping the box retains original linings and architraves and reduces disturbance to plaster, but only works when the frame is free of rot and still square.
Slim double glazed units let sash windows keep fine glazing bars and traditional proportions while improving thermal performance. Bars can be true divisions with individual units, or bars bonded to both faces of a single unit with a spacer bar between the panes, which looks very similar from a short distance.
Included as standard
- Double glazed units, with safety glass where required
- Removal of old sashes or frames and disposal
- Made-to-measure timber or uPVC sash windows
- Sealing, finishing and written guarantee terms

About Llantwit Major for this job
- Postcodes covered
- CF61 and the surrounding area, including Bridgend, Pencoed and Barry
- Coast
- Llantwit Major is about 1 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Salt-laden wind and driving rain shorten the life of paint on exposed sashes, so coastal timber windows benefit from durable timbers, good factory coatings and regular inspection. Brass or stainless sash furniture resists corrosion better than plated steel near the sea.
- Daylight and sun
- In Llantwit Major the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 hours in midsummer. Glazing bars and deep frames reduce daylight, so slimmer bars and high light-transmission low-E glass help north-facing rooms. Tall south-facing sashes can let in strong summer sun; the top sash can be lowered to vent warm air out at high level.
- Access and setting
- Older rural houses often have sash openings that are out of square, with soft stone or lime plaster around them, so each window is measured individually and fitted gently. Exposed sites benefit from draught seals and robust weatherboards on the bottom sash.
- Rules in Wales
- In Wales, Approved Document N covers safety glazing: safety glass is needed in and around doors and in low-level glazing where people could walk into it.
Guide prices in Llantwit Major
| Typical job | Guide price inc VAT |
|---|---|
| uPVC sliding sash, 900 × 1500 mm | £1,495 – £1,995 |
| Timber-effect uPVC sash, 900 × 1500 mm | £1,795 – £2,295 |
| Painted timber sash, 900 × 1500 mm | £2,595 – £3,295 |
Get a guide price for your size
In Wales, replacing a whole window or glazed external door is building work and is notified either by an installer registered with a competent person scheme or through the local authority's building control. Replacing only the glass in an existing frame is treated as a repair.
What you can choose
uPVC sliding sash
Low-maintenance uPVC frames with sculpted profiles and optional woodgrain foils, suited to homes where planning rules allow uPVC.
Heritage glass options
Slim double glazing, low-E coatings and textured glass that looks like old cylinder glass for sensitive elevations.
Spring-balanced timber sash
Timber sashes running on concealed spring balances, giving a slimmer frame where weight pockets are not needed or space is tight.
Sash Windows in Llantwit Major: questions
Should I repair or replace my sash windows?
Repair suits sashes where the timber is mostly sound and only cords, beads or small sections need attention, especially in listed or conservation properties. Replacement suits frames with widespread rot, distortion or repeated failures, or where you want double glazing and better security. A survey of each window shows which approach makes sense, and we can quote either.
How long does it take to replace sash windows?
Fitting a single sash window usually takes most of a day, longer where the box frame is removed or plaster disturbed. A whole house typically takes several days on site. The windows are made to order first, and timber sashes with special details take longer to manufacture; the lead time is confirmed in writing with your quote.
Will double glazed sashes be too heavy for my existing frame?
Double glazed sashes are heavier than single glazed ones, so the box frame, pulleys and weights must cope. When new sashes go into an existing box, the glazier checks the pulleys and adds or replaces weights so each sash balances. If the box is weak or rotten, a new frame is the better option, and the survey will tell you.
What guarantee comes with new sash windows?
Manufacturer guarantees apply to the joinery, finish, sealed units and hardware, and the terms are confirmed in writing. Cover on the paint finish often depends on regular maintenance, so check the conditions. Guarantee terms for the installation are set out in writing with your quote, so you know what is covered before agreeing to go ahead.
Do you cover Llantwit Major for sash windows?
Yes. We can quote for sash windows across Llantwit Major and the surrounding South Glamorgan area, including postcode districts CF61, and nearby Bridgend, Pencoed and Barry. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
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