- Postcode district
- W4
- Survey
- Free for new and replacement doors
- Typical lead time
- Typically 6–8 weeks for slimline systems after check survey sign-off
- Guide price
- From £5,095 inc VAT
- Nearby
- Acton, Hammersmith, Barnes
- Building rules
- England
Sliding doors for extensions and garden rooms in Chiswick: what to know
Most homeowners choosing sliding doors for extensions want the same things: more light, a clear view and a door that is easy to live with.
For a garden room at the bottom of a Chiswick garden, think about access: large glass panels need a clear route from the road to the site.
When your Chiswick extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- Slimline aluminium systems with interlocks typically around 20–25 mm maximise the glass in a new rear wall, keeping the view as open as possible.
- Agreeing a fitting date with your builder lets the extension be made weathertight on programme, so plastering and flooring can follow without waiting on the doors.
- Being involved at drawing stage means the opening is formed to suit the door, rather than the door being compromised to suit an opening built a few centimetres out.
How much sun will a door in Chiswick get?
Sun angles matter for big glazed doors. Around Chiswick, midday sun reaches about 62° in summer and drops to about 15° in winter. That low winter sun is free heat through south-facing glass; high summer sun is easier to shade with a roof overhang, and solar-control glass helps where there is none.
Typical costs for sliding doors for extensions around Chiswick
The table shows guide prices for common sizes, supplied and fitted, including VAT. Your exact price is fixed in a written quote once the opening in your Chiswick home has been measured.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 2.4 m | 2 panels | £5,995–£7,295 |
| 4.8 m | 3 panels | £9,595–£11,695 |
| 6.0 m | 4 panels | £11,395–£13,895 |
See every size on the sliding doors for extensions page or try the guide price tool.
What happens when you order sliding doors for extensions in Chiswick?
A surveyor visits your Chiswick home to check the wall, the structure above and the floor levels, and talks through glass and finish. Any building work is planned to the engineer's design, the door is made to the finished opening sizes — typically 6–8 weeks for slimline systems after check survey sign-off — and fitting usually takes 1–2 days, scheduled to the build programme.
Do you need approval in Chiswick?
In England, sliding doors in a new extension are covered by the extension's own Building Regulations application rather than a separate door notification. Approved Document L limits the glazed area: windows, roof windows and doors should not normally exceed 25% of the extension's floor area plus the area of any windows or doors lost to the extension, unless the extra glass is compensated for elsewhere. The doors must also meet the energy and safety glazing standards.
Finishes and extras for sliding doors for extensions
- Three or four panels. More panels for wider extension openings, with one or more sliding.
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in Chiswick
Do you fit sliding doors for extensions in Chiswick?
Yes. We survey and fit sliding doors for extensions in Chiswick and across Greater London, including nearby Acton and Hammersmith. Start with a guide price online or call us, and we will arrange a free survey for a new or replacement door.
How much do sliding doors for an extension cost?
Slimline sliding doors for an extension have a guide price of £7,795–£9,495 for a 3.6 m opening and £9,595–£11,695 for a 4.8 m opening, fitted, inc VAT at standard 2.1 m height. Taller doors, extra panels, special glass and flush thresholds move the price. Your written quote after the check survey fixes it.
What sliding doors suit a garden room?
A garden room usually suits a two-panel or three-panel sliding door sized to the front of the building, with a header strong enough to carry the roof without pressing on the frame. Aluminium systems are a common choice because they are stable and need little maintenance. Glass with good insulation helps if the room will be used all year.
Why does the steel beam matter for sliding doors?
The steel beam above an extension's sliding door matters because every beam bends a little under load, and a large sliding door needs a straight, level head to run freely. If the engineer knows a wide slider will sit under the beam, they can design for low deflection. Too much movement can make panels stiff or bind.

