- Postcode district
- RG9
- 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
- Marlow, Reading, Lower Earley
- Building rules
- England
What sliding doors for extensions offer homes in Henley-on-Thames
A few practical points decide whether sliding doors for extensions suit a particular room and opening:
When your Henley-on-Thames extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
If your Henley-on-Thames builder is about to pour the screed, confirm the finished floor level for the threshold first, because it is very hard to change afterwards.
- A check survey once the opening is built means the door is made to the real dimensions, accounting for any small variation in the brickwork or blockwork.
- Garden rooms benefit from the same approach, with a door sized to the frame and a header designed to carry the roof without pressing down on the door.
- 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.
Planning glass for the light in Henley-on-Thames
At the latitude of Henley-on-Thames, the midday sun climbs to about 62° in late June but only about 15° in late December, when daylight lasts around 7 h 49 min against 16 h 39 min in midsummer. A south-facing sliding door for an extension lets that low winter sun deep into the room; on a west or south elevation, solar-control glass keeps summer afternoons comfortable.
How much do sliding doors for extensions cost in Henley-on-Thames?
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 Henley-on-Thames home has been measured.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 1.8 m | 2 panels | £5,095–£6,195 |
| 3.0 m | 2 panels | £6,895–£8,395 |
| 4.8 m | 3 panels | £9,595–£11,695 |
See every size on the sliding doors for extensions page or try the guide price tool.
Timescales for sliding doors for extensions in Henley-on-Thames
Here is the usual sequence in Henley-on-Thames: guide price, free survey, written quote, any building work, then manufacture (typically 6–8 weeks for slimline systems after check survey sign-off). Fitting typically takes 1–2 days, scheduled to the build programme. Nearby, we also survey in Marlow, Reading and Lower Earley.
Rules for sliding doors for extensions in England
Doors in an English extension go through the extension's Building Regulations approval. Under Approved Document L, the total area of windows, roof windows and doors is normally capped at 25% of the extension's floor area plus any openings the extension removes, unless your designer shows compensating improvements; the glass must be safety glazing under Approved Document K.
Which options matter for sliding doors for extensions?
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in Henley-on-Thames
Do you fit sliding doors for extensions in Henley-on-Thames?
Yes. We survey and fit sliding doors for extensions in Henley-on-Thames and across Oxfordshire, including nearby Marlow and Reading. Start with a guide price online or call us, and we will arrange a free survey for a new or replacement door.
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.
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.
How do I get a level threshold in an extension?
A level or flush threshold in an extension needs the finished floor level inside to be set relative to the door sill and the outside paving before the screed goes down. Outside, a drainage channel is needed across the threshold so rain cannot run in. Our thresholds guide explains the options.

