Everything below is supplied and fitted, VAT included, for a standard RAL colour and a good but not exotic glass specification, in the area we cover. It excludes structural work, groundworks, flooring and decoration. Prices move; treat this as a way to sanity-check a quote rather than as a price list.
| Configuration | Opening | Typical range | Notes |
|---|---|---|---|
| Folding, 3 leaf | ~3.0 m | £6,000–£9,500 | Most common domestic set |
| Folding, 4 leaf | ~3.6–4.0 m | £7,500–£12,000 | Traffic door adds a few hundred |
| Folding, 5–6 leaf | ~4.8–6.0 m | £10,000–£18,000 | Split stacking common |
| Sliding, 2 panel | ~3.0 m | £6,500–£11,000 | Panel weight drives cost |
| Sliding, 3 panel | ~4.5 m | £9,500–£17,000 | Slim-interlock variants at the top |
| Single door + fixed light | ~1.8 m | £2,800–£4,800 | Often overlooked, often right |
What sits inside a supplied-and-fitted price
- Survey and manufacture to your opening
- The doors, glass, hardware and threshold
- Delivery and installation labour
- Removal and disposal of the existing frame, usually
- Perimeter sealing externally and internally
- Building control notification through a competent person scheme, usually
What sits outside it, and catches people
This is where budgets break. None of these are unreasonable exclusions — they are simply not door costs — but they need to be in the project budget from the start.
- Structural opening: steel beam, padstones, engineer's calculations, temporary propping. On a typical 3–4 m rear opening this is often £2,500–£6,000 on its own.
- Groundworks and drainage: the channel drain in front of a flush threshold, connected to something. £600–£2,000 depending on where it has to run to.
- Making good: plastering the reveals inside, rendering or brickwork outside. Some quotes include plaster-ready, almost none include decorated.
- Flooring: continuing your floor to the new threshold line, and matching what is already there.
- Scaffolding or access: rare at ground floor, occasionally needed on sloping sites.
- Electrics: the socket or light switch that was on the wall you have just removed.
- Craneage: only if access is bad, but it is four figures when it happens.
Add the door quote and the builder's quote together before deciding whether you can afford it. We have watched more than one project stall in Stevenage because the doors were budgeted at £9,000 and the opening to put them in cost another £5,500 that nobody had counted.
Why two quotes for the same opening differ by thousands
Glass. The biggest single variable after size. Moving from a basic double-glazed unit to a warm-edge, argon-filled unit with a good low-emissivity coating adds real money and real performance. Acoustic laminate or solar control adds more. Two quotes with identical frames can differ by £1,500 on glass alone.
Colour. A standard stock RAL is cheapest. A non-standard RAL adds cost and time. Dual colour means coating the profile twice.
Threshold. A flush threshold with proper drainage detail costs more than a weathered one, both in the door and in the groundwork.
Who is fitting. An employed team that has fitted the system a hundred times costs more than a subcontractor priced by the day. It is usually money well spent.
What is included. Very often the entire gap between two quotes is making good and disposal. Ask both to itemise.
Where to save, and where not to
Sensible savings: fewer, wider leaves rather than more narrow ones; a standard RAL instead of a bespoke colour; single colour instead of dual; keeping the opening the same size as the existing one so the structural work is minimal; ordering doors and windows together.
False economies: dropping the traffic door; downgrading the glass to save a few hundred on a twenty-year purchase; taking the cheapest fitter for a door that is only as good as its installation; skipping the drainage in front of a flush threshold. That last one is the most expensive saving available, because the eventual repair involves lifting paving.
Payment structure
Expect twenty to thirty per cent on order, the balance on completion. Some firms take a stage payment on delivery. Hold back at least ten per cent until after the snagging walk-through and a week of ordinary use. Pay the deposit by credit card if the value qualifies, for the statutory protection.
A note on getting comparable numbers
Write one brief and send the identical brief to every company: opening dimensions, configuration, threshold type, glass specification, RAL number, and what you expect included. Vague briefs produce vague quotes, and vague quotes cannot be compared. Local fabricators such as 5EC Alu publish enough system detail online that you can write that brief properly before anyone visits, which puts the conversation on a much better footing.
Finally: three quotes, not seven. Beyond three you are not gathering information, you are procrastinating, and lead times are six to ten weeks either way.
Common questions
How much do 3 metre bifold doors cost?
Around £6,000 to £9,500 supplied and fitted for a three-leaf set in a standard colour, in North London and Hertfordshire as of mid-2026. Structural work to form the opening is extra.
Are sliding doors more expensive than bifolds?
Slightly, for the same opening, because the panels are larger and heavier and the gear is beefier. The ranges overlap and the glass specification moves the price more than the door type does.
Why is one quote thousands cheaper?
Usually glass specification, threshold type, or whether making good and disposal are included. Ask both companies to itemise against each other and the gap normally explains itself.
Does the price include forming the opening?
Almost never. The beam, padstones, propping and engineer’s calculations are a separate builder cost, commonly £2,500 to £6,000 on a typical rear opening.