Finchley · Greater London
Sash Windows in Finchley
Rattling, rotten or stuck sashes in Finchley can often be replaced while keeping your original box frames, linings and architraves where the timber is sound.
- N3
- N12
- N2
- Guide from £1,495
Timber sash windows in Finchley
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.
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.
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.
Trickle vents can be fitted discreetly in the head of a sash frame or the top rail. In England, Approved Document F expects ventilation after window replacement to be no worse than before, although listed buildings and conservation areas may meet it only where reasonably practicable, agreed with building control.
What a typical job includes
- Sealing, finishing and written guarantee terms
- Made-to-measure timber or uPVC sash windows
- Removal of old sashes or frames and disposal
- Double glazed units, with safety glass where required
Working in Finchley
- Postcodes covered
- N3, N12, N2 and the surrounding area, including Muswell Hill, Cricklewood and Wood Green
- Coast
- Finchley is well inland, around 42 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Finchley 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 Finchley
| 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.
Options to choose between
Tilt-in sashes
Sashes that tilt inwards for cleaning upper-floor glass from inside, and can help provide an escape opening.
Replacement sashes only
New double glazed sashes fitted into your existing sound box frame, keeping original linings, architraves and plasterwork.
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 Finchley: 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.
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.
Are uPVC sash windows allowed in conservation areas?
It depends on the council. Some conservation areas and Article 4 directions require timber on front elevations, while others accept well-detailed uPVC sashes with sculpted profiles and run-through horns. Listed buildings almost always need timber. Check your council's guidance or ask the planning department before choosing uPVC, because removing unauthorised windows later is costly.
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.
Do you cover Finchley for sash windows?
Yes. We can quote for sash windows across Finchley and the surrounding Greater London area, including postcode districts N3, N12 and N2, and nearby Muswell Hill, Cricklewood and Wood Green. 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 Finchley
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.