Purley · Greater London
Sash Windows in Purley
If single glazed sashes in Purley stream with condensation every winter, double glazed replacements with draught seals can make rooms warmer and quieter.
- CR8
- CR2
- CR5
- Guide from £1,495
uPVC sliding sash windows for homes and businesses in Purley
In England, Approved Document L allows an alternative where a window must keep a building's character: a centre-pane U-value no worse than 1.2 W/m²K, or single glazing supplemented by low-E secondary glazing. Otherwise a replacement should meet 1.4 W/m²K or Window Energy Rating band B.
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.
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.
What you get
- Double glazed units, with safety glass where required
- Sealing, finishing and written guarantee terms
- Weights or balances set for smooth, even sliding
- Survey recording mouldings, horns, bars and box condition

Purley at a glance
- Postcodes covered
- CR8, CR2, CR5 and the surrounding area, including Coulsdon, South Croydon and Wallington
- Coast
- Purley is well inland, around 36 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Purley 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
- 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 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 Purley
| 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 England, replacing a whole window, roof window or glazed external door is building work. It has to be notified to building control, either by an installer registered with a competent person scheme such as FENSA or Certass, or through a building notice to the council. Replacing only the glass in an existing frame is a repair and is not notifiable.
Choosing your sash windows
Glazing bar patterns
Two over two, six over six or other bar layouts, as true divisions or bars bonded to the glass faces.
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.
uPVC sliding sash
Low-maintenance uPVC frames with sculpted profiles and optional woodgrain foils, suited to homes where planning rules allow uPVC.
Sash Windows in Purley: questions
What maintenance do timber sash windows need?
Timber sash windows need periodic repainting, how often depends on exposure, orientation and colour, plus routine checks of cords, pulleys and seals. Keep paint off the running surfaces, clean the sills and touch up chips before water gets in. Factory-finished timber lasts longer between coats than site-painted joinery, but still benefits from yearly inspection.
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.
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.
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 Purley for sash windows?
Yes. We can quote for sash windows across Purley and the surrounding Greater London area, including postcode districts CR8, CR2 and CR5, and nearby Coulsdon, South Croydon and Wallington. 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 Purley
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.