- Postcode district
- CM6
- 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
- Braintree, Bishop's Stortford, Chelmsford
- Building rules
- England
Is a sliding door for an extension a good fit for your home in Great Dunmow?
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.
Where an extension in Great Dunmow faces south or west, ask about solar-control glass, because a wall of glass in a single-storey room can overheat in summer.
Planning an extension in Great Dunmow? Send us the drawings before the steel is ordered, so the beam above the doors can be designed with the door in mind.
- 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.
- 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.
Daylight in Great Dunmow and what it means for your glass
Because Great Dunmow sees long summer days (about 16 h 43 min) and short winter ones (about 7 h 46 min), the elevation your door faces makes a real difference. With the midday sun at about 15° in winter, a south-facing door brings light well into the room; a west-facing door catches hot late-afternoon sun in summer.
Typical costs for sliding doors for extensions around Great Dunmow
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 Great Dunmow home has been measured.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 1.8 m | 2 panels | £5,095–£6,195 |
| 4.0 m | 3 panels | £8,395–£10,195 |
| 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.
How fitting works in Great Dunmow
Nothing is ordered until you sign off the surveyed specification. The door is made from 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. If you are in Braintree or Bishop's Stortford, the same process and prices apply.
Do you need approval in Great Dunmow?
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.
Choosing the specification
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
- Three or four panels. More panels for wider extension openings, with one or more sliding.
Questions about sliding doors for extensions in Great Dunmow
Is the price different in Great Dunmow?
No. Guide prices for sliding doors for extensions are the same across mainland Britain, including Great Dunmow. The fitted price depends on size, system, glass and finish, and any structural work, all fixed in your written quote after survey.
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.
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.
Can you measure from drawings rather than the built opening?
We can quote from drawings, but we manufacture from a check survey of the built opening, because real openings often differ slightly from the plans. Making a large made-to-measure door from drawings alone risks it not fitting. If a programme makes that unavoidable, any arrangement and who carries the risk would be agreed in writing first.