- Postcode district
- NN11
- 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
- Rugby, Towcester, Northampton
- Building rules
- England
Is a sliding door for an extension a good fit for your home in Daventry?
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.
If your Daventry builder is about to pour the screed, confirm the finished floor level for the threshold first, because it is very hard to change afterwards.
When your Daventry extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- Telling the engineer the door type and span early lets them design the beam above it to limit deflection, protecting the smooth running of large sliding panels.
- 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.
- 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.
Daylight in Daventry and what it means for your glass
In Daventry the shortest day has roughly 7 h 42 min of daylight and the longest about 16 h 47 min. The noon sun sits near 14° above the horizon in winter and 61° in summer — so glass that faces south collects useful warmth from October to March, while a west-facing door may need solar control to stop it overheating in July.
What should you budget for sliding doors for extensions in Daventry?
These are guide prices for fitted doors, including VAT. They run from an entry-level system to a premium one at the same size; the survey confirms which suits your opening.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 2.1 m | 2 panels | £5,495–£6,795 |
| 2.4 m | 2 panels | £5,995–£7,295 |
| 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.
Timescales for sliding doors for extensions in Daventry
Here is the usual sequence in Daventry: 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 Rugby, Towcester and Northampton.
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.
Choosing the specification
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Three or four panels. More panels for wider extension openings, with one or more sliding.
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
Questions about sliding doors for extensions in Daventry
Do you fit sliding doors for extensions in Daventry?
Yes. We survey and fit sliding doors for extensions in Daventry and across Northamptonshire, including nearby Rugby and Towcester. 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.
When should I order sliding doors for an extension?
Order sliding doors for an extension as soon as the opening is built and a check survey can be done, and agree the target fitting date with your builder in advance. Slimline doors typically take 6–8 weeks to make after sign-off. Getting a quote from drawings early means the specification is settled and only the final measurements are needed.
What structural opening size should my builder leave for sliding doors?
Your builder should leave the structural opening size we give in writing for your chosen door, which is the frame size plus a small fitting tolerance on each side and at the head. The exact figure depends on the system and the threshold detail. We confirm it from your drawings early, then check the built opening before the door is made.

