Streatham · Greater London
Sash Windows in Streatham
If single glazed sashes in Streatham stream with condensation every winter, double glazed replacements with draught seals can make rooms warmer and quieter.
- SW16
- SW12
- SE27
- Guide from £1,495
Streatham: replacement sash windows
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 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.
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 that run smoothly need routine care: keep the pulley wheels free of paint, wax or lightly lubricate the running channels, check the cords for fraying, and repaint timber before bare wood shows. Draught brush seals in the beads and meeting rails reduce rattles and heat loss.
What you get
- Made-to-measure timber or uPVC sash windows
- Weights or balances set for smooth, even sliding
- Survey recording mouldings, horns, bars and box condition
- Double glazed units, with safety glass where required

About Streatham for this job
- Postcodes covered
- SW16, SW12, SE27 and the surrounding area, including Clapham, Brixton and Mitcham
- Coast
- Streatham is well inland, around 35 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Streatham 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 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 Streatham
| 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
Listed buildings in England need listed building consent for most changes to historic windows or glass, and conservation areas can restrict changes visible from the street. Speak to the council's conservation officer before ordering.
Options to choose between
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.
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.
Sash Windows in Streatham: 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.
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.
How secure are sash windows?
New sash windows can be secure when fitted with keyed locks at the meeting rails, sash stops, laminated glass and tight-fitting beads. Older sashes often rely on a single catch, which is easily forced. Upgrading ground-floor and easily reached windows first makes sense, and the glazier can recommend locks that suit the sash and frame.
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.
Do you cover Streatham for sash windows?
Yes. We can quote for sash windows across Streatham and the surrounding Greater London area, including postcode districts SW16, SW12 and SE27, and nearby Clapham, Brixton and Mitcham. 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 Streatham
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.