Budget
£3,850
- Focused essentials
- Practical finishes
Bifold Doors Costs in London
Estimates derived from UK trade benchmark data and regional labour indices, updated May 2026. Methodology →
Bifold Doors in London typically lands above the UK-wide average for the same spec. We start from our national guide ranges and reflect the labour and logistics pressure you usually see in the capital.
In London, labour and logistics costs are typically highest across UK regions. For the full UK-wide baseline, compare with Bifold Doors Cost UK.
Two ways to take action on bifold doors costs
Pick the path that fits where you are — running early numbers, or pressure-testing a quote you've already got.
Typical London bifold doors budgets
Three planning tiers for bifold doors in London, with scope and a representative figure for each. Run your own numbers in the calculator for a tailored range.
Mid-rangeMost common
£6,700
- Balanced specification with core upgrades
- Reliable materials
Premium
£11,700
- Premium materials
- Wider scope with higher coordination demands
Typical regional cost ranges
| Item | Cost Range |
|---|---|
| uPVC bifolds (3m span) | £2,450 – £4,900 |
| Aluminium bifolds (3m span) | £4,250 – £8,500 |
| Aluminium bifolds (4–5m span) | £6,100 – £14,600 |
| Timber bifolds | £5,500 – £12,200 |
| Sliding patio (3m) | £1,850 – £4,900 |
Mini bifold doors cost calculator
Three quick inputs and we'll email you an indicative range. Run the full calculator for a postcode-adjusted estimate.
What's included in London bifold doors costs
- Size and number of panels — wider openings cost more.
- Material — uPVC is cheapest; aluminium and timber cost more.
- Glazing — double vs triple, standard vs toughened.
- Opening type — bifold vs sliding; track and hardware quality.
- Access and preparation — existing opening vs new build.
- Location — London and the South East typically cost 10–20% more.
5 line items every fair bifold doors quote should include
Use this checklist to spot missing scope before you sign — each item names what should be priced and what to ask for if it isn't.
- 1
Structural engineer + RSJ for new opening
If creating a new opening (typical for kitchen-to-garden bi-folds), you need: IStructE-registered structural engineer to size the steel beam (RSJ) supporting the wall above, plus the RSJ itself with proper pad-stones and fire protection.
Fair UK range: £500-£1,200 engineer fees; £800-£2,500 RSJ + install; £200-£500 Building Regs.
Ask: Who's the structural engineer, and is RSJ supply + install + fire protection itemised separately?
- 2
Door system — manufacturer, brand, panel count
A fair quote names the system (Origin, Reynaers, Schueco, Smart Systems for aluminium; Liniar, Veka for uPVC), the panel count (3, 4, 5, 6 leaves), and the BFRC energy rating. 'Premium aluminium bi-folds' without spec is meaningless.
Fair UK range: Origin OB-49 (£550-£900/m); Schueco/Reynaers (£900-£1,400/m); uPVC (£300-£500/m).
Ask: Which system brand and model are you quoting, panel count, and BFRC rating?
- 3
Threshold detail — low / standard / wheelchair access
Threshold height matters: low (15-25mm) is wheelchair-accessible and modern but harder to weatherproof; standard (40-65mm) is easier to seal but more visible. Cheap quotes default to standard without discussing options.
Fair UK range: Low threshold typically adds £200-£400 to total cost vs standard.
Ask: What threshold height is included, and what's the upgrade for low/level threshold?
- 4
FENSA/CERTASS registration + Part L compliance certificate
Bi-fold installation is notifiable under Building Regs Part L. Installer MUST be FENSA or CERTASS registered to self-certify, otherwise you need separate Building Control application (£200-£400). Without certificate, work is non-compliant for resale.
Fair UK range: Included free if installer registered; £200-£400 if not.
Ask: Are you FENSA or CERTASS registered, and will I receive the Part L compliance certificate post-install?
- 5
Reveal repair + internal/external sealing + decoration
After installation: silicone sealant externally, foam + caulk internally, plaster repair to disturbed walls, decoration of new reveals. Cheap quotes skip this — leaving you with gaps, exposed steel beam, and unfinished plaster.
Fair UK range: £300-£800 for proper sealing + reveal repair on a typical bi-fold install.
Ask: Is reveal repair, sealing, and decoration of new plasterwork itemised separately?
Want this run on your actual bifold doors quote? Upload it and our AI Quote Checker flags missing line items, overcharges and the questions worth asking.
7 red flags that mean you might be overcharged on a bifold doors quote
UK-specific signals — each red flag explains why it matters and the question that surfaces the truth.
Not FENSA or CERTASS registered
Why it matters: Bi-fold installation is notifiable under Building Regs Part L. Without registration, the work is non-compliant — illegal and a major issue at house sale.
Ask: What's your FENSA or CERTASS registration number? I'll verify on the public register before signing.
No structural engineer for new opening
Why it matters: Creating a new opening for bi-folds (typical for kitchen-to-garden) needs RSJ calculations. Without proper engineering, the wall above can sag, crack, or fail. Reputable installers work with named IStructE engineers.
Ask: Who's the structural engineer, are they IStructE-registered, and is fire protection on the RSJ included?
Door brand not specified, or 'premium aluminium' with no name
Why it matters: Origin (mid-premium), Reynaers/Schueco (premium), and Smart Systems (mid) are real UK brands with verifiable specs and warranties. 'Premium bi-folds' without name usually means anonymous Chinese-import products with no recourse if they fail.
Ask: What's the exact system brand, model, and BFRC rating? Can I see the product datasheet?
No BFRC energy rating or U-value mentioned
Why it matters: Building Regs Part L requires minimum WER C for replacement glazing. Bi-fold systems vary enormously in thermal performance: budget aluminium may be 1.6 W/m²K, premium triple-glazed 1.0 W/m²K. Without spec, you can't be sure of compliance.
Ask: What's the BFRC rating and U-value of the door system? Is it WER A or higher?
Per-metre cost significantly below £400 for aluminium
Why it matters: UK 2026 typical for aluminium bi-folds is £550-£900/m installed. Below £400/m usually means: cheap import system, no FENSA registration, no proper threshold, no IBG warranty, basic single-coat paint finish.
Ask: How are you achieving £X/m? Can you confirm system brand, FENSA registration, IBG warranty, and threshold spec at this price?
No mention of trickle vents
Why it matters: Trickle vents are MANDATORY under Building Regs Part F (background ventilation) for replacement door/window installations since 2022. Without them, the install fails Building Control.
Ask: Are trickle vents included on the new doors? They're required under current Part F regs.
No insurance-backed guarantee (IBG) offered
Why it matters: Bi-fold installers go bust at higher-than-average rates. An IBG (via Consumer Protection Association, FENSA Insure, or similar) means the warranty survives if the installer fails. Without IBG, manufacturer warranty + nothing.
Ask: Is the installation warranty insurance-backed? Which scheme provides the underwriting?
Spot a couple of these on your bifold doors quote? Upload it for a full red-flag scan and fair-rate comparison.
How to negotiate a bifold doors quote
A simple framework, a verbatim script you can paste into an email or text, and the topic-specific levers that move the price.
Framework
- 1Get three quotes from FENSA-registered installers (verify on fensa.org.uk). Specify: same opening width, same system brand range (Origin / Schueco / Reynaers / Smart), same panel count, same threshold height, structural works y/n. Without identical scope, comparison is impossible.
- 2Demand itemised breakdowns: structural engineer fee, RSJ + install (if new opening), door system supply, fitting, threshold, trickle vents, sealing/reveal, IBG warranty. Reject single-total quotes — too easy to lowball one element.
- 3Identify the median per major line. The total spread on bi-folds is usually 30-60% — much of it is markup on door system. The system supply spread tells you who's bulk-discounted vs marked up.
- 4Approach your preferred installer (chase FENSA + IBG + recent references over lowest price). Ask them to match the median on individual lines. Confirm BFRC rating and Part L certificate before signing.
Verbatim script
I've had three quotes for these bi-folds. Yours is competitive overall, but the door system supply line is £X above the median I've received from two other FENSA-registered installers, and the structural works line is £Y above. The other quotes specify [Origin/Schueco/Reynaers] with [panel count] and [BFRC rating]. Can you walk me through what's in your system pricing, confirm the spec is comparable, and is the warranty insurance-backed?
Topic-specific levers
- Brand selection: Origin OB-49 is mid-premium (£550-£900/m); Schueco/Reynaers are premium (£900-£1,400/m); Smart Systems is mid (£500-£800/m). For a typical UK family home, Origin or Smart Systems offers the best value.
- Panel count: 4-leaf is the sweet spot for 3-4m openings; 5-leaf adds £400-£800 with limited additional functionality. Don't over-spec panel count.
- Threshold downgrade: standard (40-65mm) threshold is £200-£400 cheaper than low; if wheelchair access isn't needed, standard is often fine.
- Combine structural with bi-fold install: have the same contractor handle the new opening and the door install — saves on coordination and RSJ-to-door interface issues.
- Off-season scheduling: bi-fold demand peaks April-September. Booking October-February often saves 10-15%.
Want to know which line items on your bifold doors quote are above market before you negotiate? Upload it for a fair-rate comparison.
10 questions to ask before hiring a FENSA-registered bi-fold installer
Vet on competence, insurance, paperwork and process — not price alone. Each question spells out the answer you want and why.
1. What's your FENSA or CERTASS registration number?
Why it matters: Mandatory for self-certification of Part L compliance. Verify on fensa.org.uk or certass.co.uk — 30-second check.
2. Are you a member of the Glass and Glazing Federation (GGF)?
Why it matters: GGF membership signals competence and provides additional consumer protection (deposit protection, mediation).
3. Can you show me 2-3 recent local bi-fold installations (last 12 months) with homeowner contact details?
Why it matters: Bi-fold issues (operating problems, seal failure, threshold leaks) typically appear at 12-24 months. Local references let you visit installs and ask about post-install experience.
4. Which system brand and model do you propose, and what's the BFRC rating?
Why it matters: Origin, Reynaers, Schueco, Smart Systems are real specifications. Vague 'premium aluminium' answers mean the installer is hedging.
5. Is the installation warranty insurance-backed (IBG)?
Why it matters: IBG via FENSA Insure or similar means the warranty survives if the installer goes bust — common in this trade. Non-IBG warranties are worthless after installer failure.
6. Who's the structural engineer for the new opening, and are they IStructE-registered?
Why it matters: Structural calculations on new openings are critical. The engineer should be IStructE-registered with current PI insurance.
7. What threshold height do you propose, and what's the upgrade for low/level access?
Why it matters: Threshold detail is often glossed over. Low threshold is more accessible but harder to weatherproof — discuss the trade-off explicitly.
8. What's your payment schedule, and what's the deposit?
Why it matters: Industry norm: 10-25% deposit, balance on satisfactory completion. Anything over 25% upfront is a structural risk.
9. Are you VAT registered, and will you provide a proper invoice?
Why it matters: VAT registration matters for warranty enforcement and IBG eligibility.
10. Do you carry public liability insurance, and at what level?
Why it matters: Bi-fold work involves access at height, glass handling, structural changes. £2M minimum public liability is industry norm; £5M for jobs over £15k.
Already chosen a FENSA-registered bi-fold installer and got a quote? Run it through our Quote Checker before you commit.
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