You’ve decided to open up your home to the garden with a new extension. Now comes the practical question every extension builder gets asked: bi-fold or French doors?
Both let in light and connect your living space to outside. But they suit different homes, budgets, and openings. As extension builders working across Essex, here’s how we help homeowners choose.
The Basics
French doors are a pair of glazed doors hinged at th0e sides, opening outwards from the centre. They work in openings from 1,200mm wide and suit most property types. They are the simpler, lower-cost option.
Bi-fold doors are made up of multiple panels that fold and slide along a track, stacking to one side when open. They work best in openings from 1,800mm upwards and create a much wider connection between indoors and out. Most modern bi-folds include a single traffic door, which is one panel that opens independently for everyday use without folding the whole system back.
Cost
This is where the two options diverge most sharply.
- French doors (supply and fit): £1,200 to £3,500 depending on material and size.
- Bi-fold doors (supply and fit): £3,000 to £8,000 or more, depending on panels, material, and configuration.
uPVC is the most affordable material for both. Aluminium costs more upfront but is more durable, lower maintenance, and better for larger openings. If you are on a tighter budget, French doors offer considerably more for your money.
Opening Size
This question often settles the debate before anything else.
French doors work well up to around 1,800mm wide. For wider openings, sidelights can be added, but the door configuration stays the same. Bi-folds are not usually made below 1,800mm. Their real strength is in wider openings of 2,400mm and above, where they can open up most or all of a rear wall.
If you have an existing opening or are replacing a window, French doors are likely the only practical fit. If you are building a new extension and want to open up the entire back of the room, bi-folds are built for that job.
Everyday Use
Most people focus on how doors look when fully open. The more important question is how you will use them day to day.
French doors are straightforward. Open one or both panels, no mechanism to maintain, no track to clean. Bi-folds are more impressive fully open but less practical in winter when you are only stepping outside briefly. Without a traffic door, you have to fold the entire system back just to let the dog out. Bi-fold tracks also collect dirt and need regular clearing to keep the system running smoothly.
Which Suits Your Home?
Choose French doors if:
- Your opening is under 1,800mm.
- Your property is traditional, period, or older in style.
- You have a small garden with limited clearance outside the door.
- Budget or low maintenance is a priority.
Choose bi-fold doors if:
- You are building an extension and want to open up a wide rear wall.
- Your opening is 2,400mm or wider.
- Indoor-outdoor living and entertaining are a priority.
- You are prepared to spend more and maintain the system.
Quick Comparison
| French Doors | Bi-Fold Doors | |
|---|---|---|
| Typical cost (supply and fit) | £1,200 – £3,500 | £3,000 – £8,000+ |
| Min. opening width | 1,200mm | 1,800mm |
| Garden clearance needed | ~900mm (outward swing) | Stack room to one side |
| Best suited to | Traditional homes, smaller openings | Extensions, wide openings, open-plan living |
| Maintenance | Low. Simple hinges and seals. | Track cleaning required. More moving parts. |
Costs are estimates for Essex in 2026. Final prices depend on material, size, and whether structural work is required.
Talk to Local Extension Builders
Home Preserver supplies and fits bi-fold and French doors across Clacton, Colchester, and North Essex. See our full range on our windows and doors page, or visit our extensions and conversions page if the doors are part of a larger project.
If your project changes the size or shape of your home, it’s worth checking whether you need approval under the Planning Portal’s guidance on extensions before work begins.
Request a free consultation. No obligation.
