- Postcode district
- KT11
- Survey
- Free for new and replacement doors
- Typical lead time
- Typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals
- Guide price
- From £6,595 inc VAT
- Nearby
- Surbiton, Woking, Kingston upon Thames
- Building rules
- England
What sliding doors for new openings offer homes in Cobham
A few practical points decide whether sliding doors for new openings suit a particular room and opening:
Turning a Cobham kitchen window into a door to the garden? Check where drains, gullies and air bricks sit outside, because they can affect the new threshold.
Living in a Cobham flat? Structural changes to an external wall almost always need the agreement of the building's owner or the other owners, so speak to them first.
- Structural calculations are included in the guide price, and the Building Regulations application is handled as part of the project, so you are not left coordinating engineers and inspectors.
- Temporary propping holds up the wall above while the masonry is cut out, keeping floors, ceilings and the roof safely supported throughout the work.
- Widening a standard patio opening to a larger span can transform how a room connects to the garden, giving a wall of glass rather than a doorway.
Planning glass for the light in Cobham
Because Cobham sees long summer days (about 16 h 36 min) and short winter ones (about 7 h 51 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.
New and widened openings for sliding doors prices in Cobham
Use these guide prices to budget for the whole job in Cobham: the door, the steelwork, making good and the engineer's calculations, including VAT. Building Control or warrant fees are charged by the council on top.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 1.5 m | 2 panels | £6,595–£7,295 |
| 1.8 m | 2 panels | £6,995–£7,795 |
| 4.0 m | 3 panels | £10,295–£11,595 |
See every size on the sliding doors for new openings page or try the guide price tool.
From survey to fitted door in Cobham
Here is the usual sequence in Cobham: guide price, free survey, written quote, any building work, then manufacture (typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals). Fitting typically takes 3–5 days of building work, then 1–2 days to fit the door. Nearby, we also survey in Surbiton, Woking and Kingston upon Thames.
Do you need approval in Cobham?
In England, forming or widening an opening is structural work that needs a Building Regulations application, structural calculations and usually a steel beam on padstones. The new door is also a controlled fitting (U-value 1.4 W/m²K or better if more than 60% glazed). If steelwork bears on a party wall, the Party Wall etc. Act 1996 may apply.
Finishes and extras for sliding doors for new openings
- Window to door conversion. Cutting down below an existing window to form a door opening to the garden.
- Low threshold detail. Adjusting floor and outside levels during the building work to allow a lower sill.
- Widening an existing door. Removing masonry each side of an old patio door to take a wider slider.
Questions about sliding doors for new openings in Cobham
How soon can you survey in Cobham?
Surveys in the KT11 district are booked at a time that suits you, and we offer survey dates when we reply to your enquiry. After you approve the written quote, manufacture is typically 4–6 weeks for the door after the opening is measured; building work scheduled around approvals.
Can you turn a window into a sliding door?
Yes, a window opening can usually be extended down to the floor and often widened to take a sliding door. The work involves removing the masonry below the window, forming a new threshold, and fitting a steel beam or lintel if the opening is widened. Drains, air bricks and floor levels outside need checking, and the work needs a Building Regulations application.
How much does it cost to widen an opening for sliding doors?
Our guide price for forming or widening an opening is £3,595 for 2.4 m and £4,495 for 4.8 m, covering steel, padstones, making good and structural calculations. The door is priced separately, and Building Control fees are set by your council. All figures are guide prices inc VAT, fixed in a written quote after we survey the wall and see what is above it.
Do I need a steel beam for sliding doors?
A widened or new opening usually needs a steel beam or a suitable lintel to carry the wall and anything above it, and for wider openings a steel beam is the usual answer. A structural engineer chooses the size and bearing details based on the loads. The beam is placed on padstones at each end to spread its load into the masonry.

