French door alternatives cost 40-60% less than a standard pair of French doors
If you are replacing or installing new back doors, the first option many homeowners consider is a pair of French doors. But the installed cost of a standard uPVC pair has risen sharply in 2026. A standard 1200mm wide set of uPVC French doors now costs between £1,200 and £2,200 fully installed, according to the Glass and Glazing Federation (GGF) trade price list (GGF 2026 market data).
French door alternatives cost 40-60% less than a standard pair. The most common option is a single hinged door with a fixed side panel, priced £600-£900 installed. Bi-fold, sliding and pocket doors offer different opening widths and costs.
- Single door with side panel costs £600-£900, saving 45-55% over French doors.
- Bi-fold doors offer 90% opening width but cost £1,800-£3,200 installed.
- Sliding patio doors start at £800-£1,400 for a 1200mm opening.
- Pocket sliding doors require 3-5 days installation, longest of all options.
- All alternatives meet DESNZ Part L 2026 U-value standards.
- French door alternatives cost 40-60% less than a standard pair of French doors
- Quick numbers cost, opening width, and U-value comparison
- A single door with a side panel is the most common French door alternative
- Bi-fold doors offer the widest opening but cost more per panel
- Sliding patio doors are the cheapest option for a wide opening
- Pocket sliding doors save indoor space but require structural work
- Eligibility and certification what to check before buying an alternative
The most common alternative is a single hinged door with a fixed side panel. That combination starts at £600–£900 installed, which represents a saving of 45-55% compared to a full French door pair. Bi-fold doors offer a different cost profile. A 3-panel bi-fold set for the same 1200mm opening costs £1,800–£3,200 installed, but it delivers a 30% wider opening than French doors. These figures are based on Checkatrade 2026 national averages and GGF installer surveys (Checkatrade 2026 averages).
Quick numbers cost, opening width, and U-value comparison
| Door type | Typical installed cost (1200mm opening) | Opening width | Central U-value (W/m²K) | Installation time (days) |
|---|---|---|---|---|
| French doors (baseline) | £1,200–£2,200 | 50% of total width | 1.4 | 1–2 |
| Single door + side panel | £600–£900 | 75% of door width | 1.4–1.6 | 1 |
| Bi-fold doors (3 panels) | £1,800–£3,200 | 90% of total width | 1.6 | 2–3 |
| Sliding patio doors (2 panels) | £800–£1,400 | 60% of total width | 1.5–1.8 | 1–2 |
| Pocket sliding doors (2 panels) | £1,500–£2,500 | 60% of total width | 1.8–2.0 | 3–5 |
Sources: GGF trade price data, DESNZ Building Regulations Part L 2026 (DESNZ Part L 2026), and MCS installer survey data (MCS register 2026).
A single door with a side panel is the most common French door alternative
The direct answer to the keyword query is a fixed side panel paired with a single hinged door. This configuration mimics the look of French doors at roughly half the cost. A side panel, also called a sidelight, can be glazed to match the door glass or solid for privacy. The door itself can open inward or outward depending on your space.
A typical installation uses a 1200mm total width split into a 900mm door plus a 300mm side panel, or a 1000mm door plus a 200mm panel. The GGF design guide for replacement doors confirms this is the most common alternative for homeowners who want the appearance of a double opening without the full cost (GGF design guide 2026).
Bi-fold doors offer the widest opening but cost more per panel
A 3-panel bi-fold system for a 1200mm opening costs £1,800–£3,200 installed. That is similar to or slightly higher than French doors, but the opening width is significantly larger. Bi-folds open to 90% of the total width, compared to 50% for French doors. That difference matters if you want to move furniture or create a seamless indoor-outdoor flow.
U-values for mid-range bi-folds average 1.6 W/m²K, while French doors achieve 1.4 W/m²K, according to DESNZ Part L 2026 compliance data (DESNZ Part L 2026). The trade-off is that bi-folds require more wall space for the panels to stack against, and they need a level threshold. That groundwork adds £200–£400 to the total cost, per MCS installer pricing data (MCS register 2026).
Sliding patio doors are the cheapest option for a wide opening
A 2-panel sliding door for a 1200mm opening costs £800–£1,400 installed, which is 30-50% less than French doors. Only one panel slides, so the opening width is 60% of the total. However, the track system allows a wider total opening of up to 2,400mm for roughly the same cost as a 1200mm French door pair.
U-values for sliding doors range from 1.5 to 1.8 W/m²K, which is slightly worse than French doors but still acceptable under Part L 2026 for replacement doors (DESNZ Part L 2026). The GGF sliding door cost data confirms this as the most budget-friendly option for a wide opening (GGF sliding door data 2026).
Pocket sliding doors save indoor space but require structural work
A 2-panel pocket sliding door for a 1200mm opening costs £1,500–£2,500 installed, similar to French doors. The key advantage is that the door slides entirely into the wall cavity, so there is no door swing indoors. That saves floor space in tight rooms or hallways.
The pocket system requires a non-load-bearing wall or a steel lintel to support the cavity. Structural engineering and lintel installation add £400–£600 to the total cost, according to FENSA installers’ 2026 survey (FENSA installer survey 2026). The trade-off is that the pocket reduces usable wall space, and the U-value is higher at 1.8–2.0 W/m²K, which means poorer insulation compared to other options (DESNZ Part L 2026).
Eligibility and certification what to check before buying an alternative
All door alternatives must be certified under FENSA or an equivalent scheme such as CERTASS or BFRC to meet Building Regulations Part L 2026 for replacement doors (DESNZ Part L 2026). If you choose bi-fold or sliding doors that include solar-control glass, check the MCS register. Solar-control glass is mandatory for south-facing openings where more than 50% of the area is glazed (MCS register 2026).
Installers must be registered with TrustMark, the government-endorsed quality scheme, or FENSA to provide a 10-year insurance-backed guarantee (TrustMark 2026). Always verify the installer’s registration before signing a contract. How to check if a door installer is FENSA registered What to do if your new door doesn't meet Part L regulations
Frequently Asked Questions
A single hinged door with a fixed side panel is the cheapest alternative, costing £600-£900 installed for a 1200mm opening according to Checkatrade 2026 averages. This represents a saving of 45-55% compared to a full French door pair.
Yes, bi-fold doors cost more. A 3-panel set for a 1200mm opening ranges from £1,800 to £3,200 installed, compared to £1,200-£2,200 for French doors, based on GGF 2026 market data.
The central U-value for a single door with a side panel ranges from 1.4 to 1.6 W/m²K, meeting DESNZ Building Regulations Part L 2026 standards according to GGF trade data.
Sliding patio doors provide a 60% opening width of the total 1200mm frame, which is wider than French doors at 50%, according to MCS installer survey data from 2026.
A single door with a side panel and sliding patio doors both take 1-2 days to install, the fastest options, based on Checkatrade 2026 national averages.
