Daventry · Northamptonshire
Sash Windows in Daventry
Our glaziers survey sash windows across Daventry, recording mouldings, horns and glazing bars so the new windows suit the house and any conservation requirements.
- NN11
- Guide from £1,495
Timber sash windows in Daventry
Many Victorian and Georgian sashes reach low to the floor. In England, Approved Document K treats glazing within 800mm of floor level as a critical location, so the lower panes of tall sash windows usually need toughened or laminated safety glass, which should be permanently marked.
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.
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.
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.
What's included
- Survey recording mouldings, horns, bars and box condition
- Removal of old sashes or frames and disposal
- Weights or balances set for smooth, even sliding
- Sealing, finishing and written guarantee terms

About Daventry for this job
- Postcodes covered
- NN11 and the surrounding area, including Rugby, Northampton and Leamington Spa
- Coast
- Daventry is well inland, around 99 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Daventry the midwinter sun reaches about 14° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 61° and 16.5 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 England
- Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Guide prices in Daventry
| 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
Replacing windows and doors with similar ones is usually permitted development for houses in England. Flats, listed buildings and homes in conservation areas or covered by an Article 4 direction can need permission, so check with the council first.
Specification choices
Timber box sash
Traditional weights, cords and pulleys in a box frame, made in engineered softwood or hardwood and factory painted to your colour.
Glazing bar patterns
Two over two, six over six or other bar layouts, as true divisions or bars bonded to the glass faces.
Tilt-in sashes
Sashes that tilt inwards for cleaning upper-floor glass from inside, and can help provide an escape opening.
Sash Windows in Daventry: questions
Do sash windows have to meet building regulations?
Yes. Replacement windows are controlled under building regulations across the UK, and the detail differs between nations. In England, the work can be self-certified by an installer registered with a competent person scheme or approved by building control. Energy, ventilation, safety glazing and escape all apply, though listed buildings may meet some standards only where reasonably practicable.
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.
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 Daventry for sash windows?
Yes. We can quote for sash windows across Daventry and the surrounding Northamptonshire area, including postcode districts NN11, and nearby Rugby, Northampton and Leamington Spa. 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 Daventry
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.