- Postcode district
- CF45
- 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
- Aberdare, Merthyr Tydfil, Tonypandy
- Building rules
- Wales
Why choose sliding doors for extensions in Mountain Ash?
Before you settle on a door type, it helps to know what sliding doors for extensions do well and what to check before you order.
Self-building in Mountain Ash or elsewhere in Mid Glamorgan? 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.
When your Mountain Ash extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- Setting the finished floor level before the screed goes down allows a low threshold, typically 15–25 mm, or a flush one with a drainage channel outside.
- 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.
- 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.
Sunlight, glass and orientation in Mountain Ash
Because Mountain Ash sees long summer days (about 16 h 40 min) and short winter ones (about 7 h 48 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.
Sliding doors for extensions and garden rooms prices in Mountain Ash
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) |
|---|---|---|
| 1.8 m | 2 panels | £5,095–£6,195 |
| 3.0 m | 2 panels | £6,895–£8,395 |
| 4.0 m | 3 panels | £8,395–£10,195 |
See every size on the sliding doors for extensions page or try the guide price tool.
How fitting works in Mountain Ash
A surveyor visits your Mountain Ash 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.
Rules for sliding doors for extensions in Wales
In Wales, sliding doors in an extension are approved as part of the extension's Building Regulations application, and the glazing must meet the Welsh energy and safety glazing requirements, including the limits on how much of an extension can be glazed.
Choosing the specification
- Three or four panels. More panels for wider extension openings, with one or more sliding.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
- 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 Mountain Ash
Do I need building approval for sliding doors for extensions in Mountain Ash?
In Wales a replacement door must meet the Building Regulations as applied in Wales, arranged through a registered installer or Building Control. We confirm the right route for your property at survey, so the paperwork is in place before fitting.
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.
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.