Lisburn · County Antrim
Sash Windows in Lisburn
We cover Lisburn and the rest of County Antrim for sash window replacement, from one rotten bay sash to a full set for a Victorian or Georgian house.
- BT27
- BT28
- BT17
- Guide from £1,495
About uPVC sliding sash windows in Lisburn
A traditional box sash hides cast-iron or lead weights inside the side boxes of the frame, connected to each sash by cords running over pulleys. Modern sash windows often use spiral or spring balances instead, which take up less depth and suit uPVC and some new timber designs without weight pockets.
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.
Timber sash windows are usually made from engineered softwood or durable hardwoods, factory primed and finished with microporous paint that lets moisture escape. Factory finishing gives a more even coat than painting on site, but timber still needs periodic redecoration, and the interval depends on exposure and colour.
Sash window prices depend on size, timber or uPVC, whether you replace the whole frame or just the sashes, the glazing bar pattern, horns and mouldings, glass type and the paint colour. Listed or conservation work that needs matching details costs more. See the guide prices for typical ranges.
What you get
- Double glazed units, with safety glass where required
- Made-to-measure timber or uPVC sash windows
- Survey recording mouldings, horns, bars and box condition
- Sealing, finishing and written guarantee terms

Lisburn at a glance
- Postcodes covered
- BT27, BT28, BT17 and the surrounding area, including Carryduff, Belfast and Castlereagh
- Coast
- Lisburn sits roughly 12 km from the nearest coastline, close enough that exposure on open or high ground is worth considering. 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 Lisburn the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.0 hours of daylight, rising to about 59° and 17.0 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
- Terraced streets and conservation areas often control sash details on front elevations, so check requirements before ordering. Flats need planning permission and freeholder consent, and upper-floor sashes are usually fitted from inside, with careful protection of communal stairs and hallways.
- Rules in Northern Ireland
- Technical Booklet V covers safety glazing in Northern Ireland, including glass in and around doors and low-level glazing where people could walk into it.
Guide prices in Lisburn
| 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
Technical Booklet K covers ventilation in Northern Ireland, so replacement windows should keep adequate background ventilation.
Specification choices
Replacement sashes only
New double glazed sashes fitted into your existing sound box frame, keeping original linings, architraves and plasterwork.
Tilt-in sashes
Sashes that tilt inwards for cleaning upper-floor glass from inside, and can help provide an escape opening.
Glazing bar patterns
Two over two, six over six or other bar layouts, as true divisions or bars bonded to the glass faces.
Sash Windows in Lisburn: questions
How much do sash windows cost?
The cost of sash windows depends on size, material, whether you replace the whole frame or only the sashes, the glazing bar pattern, the glass and the finishing details such as horns and mouldings. Timber usually costs more than uPVC, and listed building work costs more again. See the guide prices for typical ranges; the written quote fixes your price.
Can I have double glazed sash windows in a listed building?
Sometimes, but listed building consent is needed for significant works, and some councils will only accept repair of the original windows or slim double glazing with matching details. Secondary glazing is often accepted where new windows are not. Speak to your council's conservation officer before ordering; we can provide drawings and specifications to support an application.
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.
Do you cover Lisburn for sash windows?
Yes. We can quote for sash windows across Lisburn and the surrounding County Antrim area, including postcode districts BT27, BT28 and BT17, and nearby Carryduff, Belfast and Castlereagh. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Lisburn
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.