- Postcode district
- IP18
- 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
- Beccles, Lowestoft, Great Yarmouth
- Building rules
- England
Sliding doors for extensions and garden rooms in Southwold: what to know
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 Southwold 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 Southwold faces south or west, ask about solar-control glass, because a wall of glass in a single-storey room can overheat in summer.
- 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.
- 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.
- 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 Southwold and what it means for your glass
The midday sun over Southwold ranges from about 14° at the winter solstice to about 61° at midsummer. Low-angle winter light reaches further into a room through a tall door, which is one reason taller panels are worth considering; on south or west walls, pair them with solar-control glass.
Guide prices for sliding doors for extensions in Southwold
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) |
|---|---|---|
| 2.1 m | 2 panels | £5,495–£6,795 |
| 3.0 m | 2 panels | £6,895–£8,395 |
| 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.
From survey to fitted door in Southwold
Here is the usual sequence in Southwold: guide price, free survey, written quote, any building work, then manufacture (typically 6–8 weeks for slimline systems after check survey sign-off). Fitting typically takes 1–2 days, scheduled to the build programme. Nearby, we also survey in Beccles, Lowestoft and Great Yarmouth.
Do you need approval in Southwold?
Doors in an English extension go through the extension's Building Regulations approval. Under Approved Document L, the total area of windows, roof windows and doors is normally capped at 25% of the extension's floor area plus any openings the extension removes, unless your designer shows compensating improvements; the glass must be safety glazing under Approved Document K.
Which options matter for sliding doors for extensions?
- 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.
- 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 Southwold
Do you fit sliding doors for extensions in Southwold?
Yes. We survey and fit sliding doors for extensions in Southwold and across Suffolk, including nearby Beccles and Lowestoft. Start with a guide price online or call us, and we will arrange a free survey for a new or replacement door.
How do I get a level threshold in an extension?
A level or flush threshold in an extension needs the finished floor level inside to be set relative to the door sill and the outside paving before the screed goes down. Outside, a drainage channel is needed across the threshold so rain cannot run in. Our thresholds guide explains the options.
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.
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.

