Sash windows · Greater London
Triple glazed sash windows in Barnet
We arrange surveys and fitting of triple glazed sash windows in Barnet and the EN5 area, with a written, fixed quote after a free survey.
Vertical sliding sashes, made triple glazed where the design allows. A sash window has one or two sashes that slide up and down in a box frame.
Winter light and glass choice in Barnet
In Barnet, midday sun in late December sits around 15° high, with roughly 7 h 48 min of daylight. For windows facing north or shaded by neighbours, cutting heat loss matters more than solar gain; on open south-facing glass, ask about a higher solar-gain unit.
Guide prices in Barnet
| Guide | Supply and fit, inc VAT |
|---|---|
| Small window about 600 x 1000 mm (bathroom, landing) | £1,295 – £1,595 |
| Medium window about 1200 x 1200 mm (bedroom) | £1,695 – £2,095 |
| Large window about 1800 x 1200 mm (lounge) | £2,595 – £3,195 |
Guide prices. Your written quote after the free survey fixes the price for the specification shown.
Rules for sash windows in England
The rules for replacement windows in England are set by Approved Document L (2021 edition, with 2023 amendments): 1.4 W/m²K, or a Window Energy Rating of band B or better. Replacement windows are a controlled fitting. A competent person scheme installer (such as FENSA or Certass) self-certifies the work and notifies the council within 30 days; otherwise a building control body approves it.
Before ordering: Replacing windows on a house is normally permitted development if the new ones look similar. New upper-floor windows in a side wall must be obscure glazed and fixed, or open only above 1.7 m. Flats and maisonettes have no householder permitted development rights, so a change that alters their appearance needs planning permission. An Article 4 direction in a conservation area may mean permission is needed, and listed buildings need listed building consent.
How it works
The surveyor measures every opening, checks ventilation, escape windows and safety-glass zones, and talks through styles. Your written quote lists each item with its glass build-up and U-value, and the price is fixed for that specification.
- Every opening measured, including escape and vent needs
- Frames rated for the weight of triple glass
- Old windows removed and taken away
- Each opening closed up the same day
Questions from Barnet
Will triple glazing make my sashes heavy to lift?
The balances are sized for the sash weight, so they should slide smoothly. Heavier sashes use stronger balances or weights.
Can I keep my original sash boxes?
Sometimes. A timber specialist can fit new sashes into sound original boxes, but the glass thickness is limited by the sash depth.
Do I need permission for triple glazed sash windows in Barnet?
In England, like-for-like replacements on a house are normally permitted development; flats need permission if the change alters their appearance, Article 4 areas may need permission, and listed buildings need listed building consent. Check whether your street is in a conservation area or covered by an Article 4 direction before changing the style.
How long does it take to get triple glazed sash windows fitted in Barnet?
After the survey, typical manufacture time is 6 to 10 weeks, and most homes are fitted in 1 to 4 days.
Nearby
Nearby towns on our list include Hadley Wood (3 km), Potters Bar (5 km), Borehamwood (5 km) and Finchley (6 km).
Other products in Barnet
- uPVC windows
- Aluminium windows
- Timber windows
- Alu-clad timber windows
- Casement windows
- Flush casement windows
- Tilt and turn windows
- Bay and bow windows
- Fixed and picture windows
- Composite front doors
- French doors
- Sliding patio doors
- Bifold doors
- Glass-only replacement
- Acoustic triple glazing
- Security glazing
- Whole-house replacement
- New builds and self-builds
- Period homes and conservation areas
- Flats and apartments
- Passivhaus and EnerPHit
Sash windows in Barnet: book your free survey
Written quote fixed for the specification, after a free survey. Building Regulations sign-off by a competent person scheme installer or building control, as the law requires in England.