- Postcode district
- SG5
- 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
- Letchworth Garden City, Stevenage, Luton
- Building rules
- England
What sliding doors for extensions offer homes in Hitchin
The right door depends on the opening, the room and the way you use the garden. Here is how sliding doors for extensions tend to work out in practice:
Self-building in Hitchin or elsewhere in Hertfordshire? Ask for the sliding doors to be quoted as part of a wider glazing package so the frames, colours and glass match across the house.
Where an extension in Hitchin faces south or west, ask about solar-control glass, because a wall of glass in a single-storey room can overheat in summer.
- 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.
- We provide the structural opening size and fitting tolerances in writing, giving your builder a clear target and avoiding disputes about who measured what.
- 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.
Daylight in Hitchin and what it means for your glass
Sun angles matter for big glazed doors. Around Hitchin, midday sun reaches about 61° 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 Hitchin
Guide prices are the same across Hertfordshire. They cover the door supplied and fitted into a prepared opening, including VAT, with options itemised in your quote.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 3.6 m | 2 panels | £7,795–£9,495 |
| 4.0 m | 3 panels | £8,395–£10,195 |
| 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 Hitchin
A surveyor visits your Hitchin 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 Hitchin?
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
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
Questions about sliding doors for extensions in Hitchin
Can you match other doors and windows in my Hitchin home?
Usually, yes. Most aluminium and uPVC systems come in standard RAL colours and finishes, and we can quote dual colour where the inside and outside need to differ. Bring photos of existing frames to the survey.
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.
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.
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.

