- Postcode district
- DH1
- 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
- Chester-le-Street, Houghton-le-Spring, Stanley
- Building rules
- England
Are sliding doors for extensions right for your Durham home?
A few practical points decide whether sliding doors for extensions suit a particular room and opening:
Where an extension in Durham faces south or west, ask about solar-control glass, because a wall of glass in a single-storey room can overheat in summer.
When your Durham extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- 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.
- 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.
- We provide the structural opening size and fitting tolerances in writing, giving your builder a clear target and avoiding disputes about who measured what.
Sunlight, glass and orientation in Durham
The midday sun over Durham ranges from about 12° at the winter solstice to about 59° at midsummer. Low-angle winter light reaches further into a room through a tall door, which is one reason taller panels are worth considering; on south or west walls, pair them with solar-control glass.
How much do sliding doors for extensions cost in Durham?
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) |
|---|---|---|
| 3.0 m | 2 panels | £6,895–£8,395 |
| 3.6 m | 2 panels | £7,795–£9,495 |
| 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 Durham
Surveys in the DH1 district are booked at a time that suits you. Once the opening is ready and measured, manufacture is typically 6–8 weeks for slimline systems after check survey sign-off; on fitting day the frame is set level and sealed, and the panels are adjusted so they glide properly. Fitting usually takes 1–2 days, scheduled to the build programme.
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
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Three or four panels. More panels for wider extension openings, with one or more sliding.
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
Questions about sliding doors for extensions in Durham
Do I need building approval for sliding doors for extensions in Durham?
In England a replacement door is a controlled fitting, so compliance is arranged through a competent person scheme installer or Building Control; new openings need a Building Regulations application. We confirm the right route for your property at survey, so the paperwork is in place before fitting.
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.
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.
Can you work with my builder and architect?
Yes, working with your builder, architect and structural engineer is the normal way we approach extension doors. We can provide technical details, opening sizes, threshold requirements and fixing information, and attend site for the check survey. Your builder forms the opening and prepares the floor, and our installers fit the doors to the agreed programme.