- Postcode district
- CF61
- 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
- Cowbridge, Bridgend, Barry
- Building rules
- Wales
Is a sliding door for an extension a good fit for your home in Llantwit Major?
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.
When your Llantwit Major extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
Where an extension in Llantwit Major 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.
- 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.
- 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.
Daylight in Llantwit Major and what it means for your glass
Sun angles matter for big glazed doors. Around Llantwit Major, midday sun reaches about 62° 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.
Guide prices for sliding doors for extensions in Llantwit Major
Guide prices are the same across South Glamorgan. 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) |
|---|---|---|
| 2.4 m | 2 panels | £5,995–£7,295 |
| 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.
What happens when you order sliding doors for extensions in Llantwit Major?
Surveys in the CF61 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 Wales
An extension in Wales needs Building Regulations approval, which covers its doors. The Welsh energy guidance limits the glazed area of an extension unless it is compensated for elsewhere, and glass in doors must be safety glazing.
Which options matter for sliding doors for extensions?
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
- Three or four panels. More panels for wider extension openings, with one or more sliding.
Questions about sliding doors for extensions in Llantwit Major
Do I need building approval for sliding doors for extensions in Llantwit Major?
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.
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.
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.

