Sash windows · Greater London
Triple glazed sash windows in Westminster
We arrange surveys and fitting of triple glazed sash windows in Westminster and the SW1P 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 Westminster
On the shortest day, Westminster gets about 7 h 50 min of daylight and the midday sun reaches only about 15° above the horizon. Low winter sun means north-facing rooms here gain little solar heat, which is where triple glazing’s lower heat loss helps most.
Guide prices in Westminster
| 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
In England, replacement windows must meet 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.
Planning: 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
You will know exactly what you are buying: the quote states the unit build-up, frame, finish, fitting work and how Building Regulations compliance is handled. On fitting day each opening is replaced and closed up before the team moves on.
- 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 Westminster
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.
How much do triple glazed sash windows cost?
Our guide starts at £1,295 for a small uPVC sash, fitted and inc VAT. Timber sashes cost more; UK quotes for timber triple sashes run past £3,000 each.
How long does it take to get triple glazed sash windows fitted in Westminster?
After the survey, typical manufacture time is 6 to 10 weeks, and most homes are fitted in 1 to 4 days.
Do I need permission for triple glazed sash windows in Westminster?
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.
Nearby
Nearby towns on our list include Pimlico (1 km), Chelsea (3 km), Battersea (3 km) and Brixton (4 km).
Other products in Westminster
- 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 Westminster: 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.