- Postcode district
- TR11
- 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
- Truro, Redruth, Helston
- Building rules
- England
What sliding doors for extensions offer homes in Falmouth
A few practical points decide whether sliding doors for extensions suit a particular room and opening:
Self-building in Falmouth or elsewhere in Cornwall? 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 Falmouth extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- Garden rooms benefit from the same approach, with a door sized to the frame and a header designed to carry the roof without pressing down on the door.
- 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.
- 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.
Light and sun in Falmouth
At the latitude of Falmouth, the midday sun climbs to about 63° in late June but only about 16° in late December, when daylight lasts around 8 h 03 min against 16 h 24 min in midsummer. A south-facing sliding door for an extension lets that low winter sun deep into the room; on a west or south elevation, solar-control glass keeps summer afternoons comfortable.
Sliding doors for extensions and garden rooms prices in Falmouth
Guide prices are the same across Cornwall. 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) |
|---|---|---|
| 1.8 m | 2 panels | £5,095–£6,195 |
| 2.1 m | 2 panels | £5,495–£6,795 |
| 3.0 m | 2 panels | £6,895–£8,395 |
See every size on the sliding doors for extensions page or try the guide price tool.
From survey to fitted door in Falmouth
A surveyor visits your Falmouth 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 England
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.
Specification choices for sliding doors for extensions in Falmouth
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
- 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 Falmouth
Do you fit sliding doors for extensions in Falmouth?
Yes. We survey and fit sliding doors for extensions in Falmouth and across Cornwall, including nearby Truro and Redruth. 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.
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.
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.