Sash windows · Dorset
Triple glazed sash windows in Dorchester
Looking at triple glazed sash windows for a home in Dorchester? We survey, quote and fit across Dorset, and the DT1 postcode district is part of that.
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 Dorchester
Winter days in Dorchester are short: about 7 h 58 min of daylight on 21 December, with the sun peaking near 16°. That low angle reaches deep into south-facing rooms, so we match the glass to each elevation rather than using one spec for the whole house.
Guide prices in Dorchester
| 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
We start with a survey, not a sales pitch: measurements, the structure above any bays, trickle-vent needs and escape windows. The quote that follows fixes the price, and anything unexpected on the day is agreed with you first.
- 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 Dorchester
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.
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.
Do you fit triple glazed sash windows in Dorchester?
Yes. We arrange surveys and fitting in Dorchester and across Dorset. Send your postcode and the windows or doors you want replaced, and we will book a free survey.
Do I need permission for triple glazed sash windows in Dorchester?
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 Weymouth (12 km), Bridport (23 km), Yeovil (29 km) and Poole (32 km).
Other products in Dorchester
- 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 Dorchester: 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.